Road curve superelevation design: current practices and proposed approach

Size: px
Start display at page:

Download "Road curve superelevation design: current practices and proposed approach"

Transcription

1 27 Road curve superelevation design: current practices and proposed approach G. Kanellaidis Abstract Horizontal alignment design standards in the United States and Australia have two basic common features: firstly the absence of a single nationwide maximum superelevation rate and secondly designers' freedom in applying above-minimum values for curve radii. Taking into account the proven dependence of operating speed on curve radius Australian standards introduce the concept of speed environment (characterising highway sections as a whole) to be used alongside the traditional design speed concept (corresponding to individual curves) and incorporate consistency checks as a feedback loop in the design process. Neither of these safeguards is explicitly included in American guidelines. Still in both countries a variety of maximum-superelevation values is used meaning that identically-designed curves (having equal radius and superelevation values) may have resulted from application of different design speeds. In this paper a proposal for simplifying the relationship between radius and superelevation is applied to Australian guidelines for speed environments ranging between 60 km/h and 120 km/h. Consistent application of this proposal for which specification of nationwide maximum superelevation rates is a precondition would result in curve radius serving the driver both as a guide for selecting speed and as a signal for the centrifugal acceleration to be expected thus enhancing horizontal alignment consistency. Refereed Paper This paper has been critically reviewed by at least two recognised experts in the field. Originally submitted: December 1998

2 28 INTRODUCTION Horizontal alignment design policy for rural roads has traditionally been based on the concept of design speed. However interesting differences are noted in the way that concept is selected and applied in various countries. In several national practices the need has been recognised for design speeds to be more directly based upon actual speed behaviour as well as for checking alignment design on the basis of estimated operating speeds (ERSF 1996; Krammes and Garnham 1995). The basic principle of horizontal curve design is derived from application of the kinematics equation according to which the total lateral acceleration applied through pavement superelevation and tyre pavement friction on a vehicle negotiating a circular curve should be equal to the centrifugal acceleration (CA) due to vehicle movement: CA = _1( = (e +f )g where V is vehicle speed (in m/s) R is curve radius (in m) e is pavement superelevation rate f is the tyre pavement side-friction factor and g is acceleration due to gravity (in m/s2). Application of the design speed concept involves the assumption of a design speed (Vd). For that speed a corresponding side-friction factor value (fvd) is also specified; fvd is commonly a decreasing function of Vd. The designer may select from different possible pairs of values for R and e that satisfy Equation (1) subject to a number of constraints. The most important constraint is that superelevation should fall within a minimum/maximum range the maximum of which (emax) could reflect the risk of stationary vehicles sliding on icy or frozen pavement surfaces. Thus the minimum radius (Rmin) is calculated as follows: Vd = 127 Rmin (emax fvd (2) where Vd is in kilometres per hour (km/h) and R.in is in metres (m). [The numerical coefficient results from conversion between different speed units and multiplication by the value for acceleration due to gravity: (3.6)2 x ] Designers are generally allowed the freedom of applying flatter above-minimum radii for the same design speeds. From Equations (1) and (2) it follows that the sum of (e + f) is reduced proportionally to the increase of R. To achieve that reduction it is common to both apply lower values for e and assume lower values for f. However there is a limiting (minimum) value for the superelevation rate (emin) equal to the rate applied (for the purpose of drainage) in tangent sections. It is noted that above a threshold radius value cross-slope is designed in the same way as for tangent cross-sections. Typically this is the so-called crown section which for these very flat curves provides negative ('adverse') superelevation equalling emin for vehicles moving on the outside of a curve. Diverse procedures are applied internationally regarding not only the design speed concept but also: maximum superelevation rates (1) values of f in relation to the design speed and application of e and f values in curves of aboveminimum radius. The following sections illustrate similarities and differences in the design approaches of the United States (AASHTO 1994) and Australia (Austroads 1993) as regards the above elements of horizontal curve design. Based on empirical findings research suggestions have been made for possible improvements to existing practices. This paper presents a proposal for curve superelevation design on the basis of a simple and consistent relationship between curvature and superelevation. The paper concludes with a summary of main points and identification of issues for further research. DISCUSSION OF EXISTING HORIZONTAL ALIGNMENT DESIGN PRACTICES IN THE UNITED STATES AND AUSTRALIA Design speed The United States (AASHTO 1994) follows what can be called a 'classical implementation' of the design speed concept (Krammes and Garnham 1995). Design speed (Vd) is chosen based on road classification land use and terrain and it is presumed that Vd will not be exceeded.

3 29 Australian guidelines (Austroads 1993) in contrast define the following four 'speed parameters': (1) desired speed defined as the free speed likely to be adopted by drivers on tangents and other less-constrained elements; (2) speed environment which is numerically equal to the desired speed of the 85th percentile driver and is used to characterise a full road section; (3) design speed applying to individual geometric elements; and (4) limiting curve speed standard defined as the speed beyond which f will exceed its design value (for a given design speed). Especially for speed environments of less than 100 km/h the Australian guidelines recognise that individual curve geometry is determined by but also helps to determine the 85th percentile speed. Thus consistency must be ensured at an early stage by using trial alignments/iterations. Maximum superelevation Both in US (AASHTO 1994) and Australian guidelines (Austroads 1993) a range of possible values for the maximum superelevation rate (emax) is foreseen. This practice can be attributed to the federal structure of both countries (whereby statelevel authorities have the liberty of setting their own limits) as well as their expansion over a large geographical area with varied climatic conditions. The latter is an important factor in defining emax values: in the case of wet or icy pavement conditions superelevation rates of 0.10 or above may be unsafe for slow-moving or still-standing vehicles (especially when tyre quality is poor). In the US the commonest emax values for interurban links are and 0.10; sometimes the more extreme values of 0.12 (provided that snow and ice do not exist) or 0.04 (preferred in urban design) are used. In Australian guidelines recommended emax values range from 0.10 (or sometimes 0.12) in mountainous terrain to 0.06 to 0.07 in flat terrain. The observed variability in emax values in both countries despite having a justification based on the climatic variability (different probability of ice or snow) does not help achieve nationwide consistency in the countries concerned. It can be proven for example that identical curves may have resulted from the application of US guidelines for different design speeds depending on whether the assumed maximum superelevation is or 0.10 (Hayward 1980; Kanellaidis 1991; Krammes 1994). Overall higher emax values (0.10 and above) may be inadvisable even for areas with a low probability of wet or icy pavement conditions since excessive superelevation may mean that drivers of slow moving vehicles (e.g. trucks) can be subjected to negative side friction causing them to steer in the opposite direction to that of the curve. Such situations are undesirable and potentially hazardous for the drivers involved. Side-friction factor in relation to the design speed In the US the design values for side-friction factor (f) have been determined on the basis of experiments using a 'ball-bank indicator' conducted in the 1930s and 1940s in which the main criterion is 'the point at which the centrifugal force is sufficient to cause feelings of discomfort to drivers' (AASHTO 1994). According to the AASHTO guidelines the f is a decreasing function of the design speed changing linearly from 0.16 for 50 km/h to 0.14 for 80 km/h and then linear again but with a steeper slope to 0.10 for 110 km/h and for 120 km/h. In Australian guidelines (Austroads 1993) the design values for f have been derived from observations of driver speed behaviour on rural road curves. For speeds above 90 km/h design values are in excess of those likely to be required by the 85th percentile driver. The function of design f against design speed in Australia follows an inverse S-shape; it changes linearly from 0.35 (50 km/h) to 0.31 (70 km/h) falling steeply to 0.12 for 100 km/h and 110 km/h (and to 0.11 for 120 km/h and 130 km/h). The main hazards from vehicle movement on a curve at an excessive speed are skidding and rollover. For the majority of vehicles the critical f values for skidding and rollover far exceed the design values assumed by highway design guidelines (Harwood and Mason 1994) with the possible exception of trucks where instability can occur at values near the Australian guidelines' f value for 50 km/h (0.35). The assumed f values in US and Australian guidelines are decreasing functions of design speed. Empirical data reveal thatf values 'acceptable' by drivers are also higher for lower speeds (McLean 1981; Krammes 1994).

4 30 Furthermore empirical evidence suggests that the f values accepted by drivers are well in excess of the assumed values especially for lower speeds (below 90 kph) (McLean 1981; Lamm et al. 1989; Krammes 1994). It may be thus concluded that assumed f values are at least at lower speeds conservative in comparison to the f values acceptable by the 85th percentile driver (f85). Table 1 presents (for the speed range of 60 km/h to 120 km/h) a comparison of assumed f values in US and Australian guidelines. Superelevation and side-friction values in curves of above-minimum radius The procedure described in United States guidelines (AASHTO 1994) recognises the possibility that curves with above-minimum radius will be overdriven (driven at speeds above the design speed) but makes no corrections to the design speed. Rather it provides an increasing ratio of e over f for increasing curve radius resulting in a parabolic relationship between e and the inverse of R (1/R). The limiting value emirs is equal to In Australian guidelines (Austroads 1993) it is only mentioned that when above-minimum radii are selected the corresponding superelevation and side friction values are 'below their maximum values'. No exact calculations are made and no special graphs are developed for above-minimum radii. However the limiting curve speed standard is for given e and R values the speed at which the corresponding design value off is reached thus indirectly providing a lower limit. Minimum superelevation values range from 0.02 to 0.03 the latter value being typical for bituminous pavements. Discussion on the effect of curvature and superelevation on driving behaviour There is ample and consistent empirical evidence linking operating speed to radius of curvature. Relationships have been developed over the years showing that the inverse of curve radius 1/R can be a good predictor of speed (Taragin 1954; Lamm et al. 1989; Kanellaidis et al. 1990; Ottesen and Krammes 1994). In current US design practice (AASHTO 1994) it is usually assumed that the design speed is unchanged that is unaffected by changes in curvature. Thus curves of an above-minimum radius only serve to reduce the total centrifugal acceleration requirement (e + f) which is directly proportional to degree of curve (or inversely proportional to curve radius). However this consideration does not take into account the fact that operating speed is affected by the horizontal alignment. In certain cases this omission may lead to a serious underestimation of operating speed. This question is addressed in a different way in Australian guidelines (Austroads 1993) where design speed does not correspond to a whole section but to individual elements. Thus given a speed environment design speed for a horizontal curve is Table 1 Assumed side-friction factors (f) in design guidelines of the United States and Australia for speeds between 60 km/h and 120 km/h Design speed Vd (km/h) AASHTO (United States) Assumed side friction factors (f ) Austroads (Australia)

5 31 a function of that speed environment and the curve radius as shown in Figure 2.2 of the Australian guidelines. With the help of an iterative process (using trial alignments subject to consistency checking) the Australian guidelines provide the potential for abetter matching between design speed and actual operating velocities. However in both countries given regional differences in maximum superelevation rates it is possible that identical curves (that is having equal radii and superelevation rates) correspond to different design speeds. A large diversity of superelevation rates and the lack of a clear association between superelevation and curvature have been observed (Krammes 1994). Also there is empirical evidence that superelevation does not have a significant influence on driving behaviour parameters such as operating speed (Gambard and Louah 1986) or acceptable f values (Kanellaidis and Dimitropoulos 1995). Thus although the dynamics of vehicle movement show that the selection of superelevation is important for traffic safety research findings suggest that it does not make much of a difference for drivers who are primarily affected by the radius of curvature in choosing their speed. Therefore there appears to be a case for highway design practice to provide a clearer link between speed curvature and superelevation; this would further refine the link between curvature and speed environment that is already inherent in Australian practice. If a given curve radius corresponded to a certain (and appropriately selected) superelevation rate then the speed chosen because of that radius would result in a specific (and acceptable) level of overall lateral acceleration (e + f). Thus the radius would serve the driver not only as a guide as to the speed to be chosen but also as a signal for the centrifugal acceleration to be expected. In this manner the consistency of the alignment could be further enhanced. PROPOSAL FOR IMPROVING CURVE SUPERELEVATION DESIGN PRACTICE Compared to other countries' practices the Australian horizontal alignment design procedure (Austroads 1993) follows a considerably advanced approach in dealing with the issue of providing a proper matching between assumed and actual speeds. The selection of design speed is not made through what has elsewhere been criticised as an 'arbitrary' process. On the contrary the influence of alignment design (and especially curve radius) on operating speeds is recognised and the Australian definition of design speed corresponds to individual curves (as contrasted to 'speed environment' which characterises a whole highway section). Through an iterative procedure alignment is fine-tuned so as to help attain both consistency of successive curves and harmonisation between assumed and operating speeds. The concept of using an assumed speed for the whole section together with assumed speeds for individual elements the latter being more closely related to expected actual speeds is applied in a similar form in Italy (Krammes and Garnham 1995) where the 'range' of design speeds is the equivalent of the speed environment. Kanellaidis and Dimitropoulos (1995) have mentioned a similar twostage concept for curve design consisting of design speeds (defining the minimum radius) and 'speed standards' (corresponding to a range of radius values); speed standards may be higher (but not lower) than the design speed reflecting the fact that at these flatter curves operating speed may exceed the design speed. In addition the importance of horizontal alignment consistency (given the effect of horizontal curvature on operating speeds) should not be underestimated (Leisch and Leisch 1977; Messer et al. 1981; Lamm et al. 1992; Krammes 1994). Large operating-speed differentials are known to be correlated to increased accident occurrence (Anderson and Krammes 1994). Australian guidelines are among those incorporating research proposals for design standards to include consistency checks as a 'feedback loop' (Lamm et al. 1992; Kanellaidis 1996). If the designers' liberty of applying above-minimum radius values is to be preserved (and indeed it may be unnecessarily restrictive to do away with aboveminimum design altogether) it is important to ensure that above-minimum design does not lead to potential safety problems. Flatter curves are associated with higher operating speeds and due to conservative assumptions for the design f design speed is (even at minimum-radius curves especially in US standards) an underestimation of operating speed. Therefore design guidelines should be enhanced with additional consistency safeguards regarding above-minimum design.

6 32 One important inconsistency factor is the variety of emax values applicable in the practices of Australia the United States and other countries. It has been argued that agreement on a single emax value possibly at the rate of 0.08 (assuming high-type pavements) would be beneficial and feasible contributing to greater consistency (Craus and Livneh 1978; Kanellaidis 1991; Krammes 1994). In addition simplification of the radius superelevation relationship so that there is a one-toone correspondence between R and e could also lead to greater consistency as already discussed. The idea of simplifying the R e relationship is not new. There have been arguments and actual proposals for a change in that direction (Koeppel 1986; Kanellaidis 1991; Nicholson 1998). This paper presents the possibility of applying such a proposal defined originally by Kanellaidis and Dimitropoulos (1995) to the design of two-lane rural roads in Australia. In applying this proposal it is assumed that the designer follows the recommendations of Australian guidelines regarding the selection of speed environment. Within the selected speed environment design speed for individual curves is defined in association with the chosen radius (Austroads 1993). The proposal's innovation lies in the introduction for each speed environment of a one-to-one correspondence between radius and superelevation. The proposal is based on four criteria. The first two are given in Australian design guidelines whereas the additional criteria correspond to additional safety considerations suggested by research. Criterion 1: Superelevation should be between emin and emax For Australian nationwide consistency it is proposed that these values are set at 0.02 and 0.08 respectively. Criterion 2: The side friction factor should not exceed the specified maximum value fmax' corresponding to the speed environment as defined in Australian standards (see Austroads values in Table 1). Criterion 3: The portion of the total sideways force that is provided by superelevation that is the ratio of e over (e + f) should be higher than a desirable minimum value to provide a satisfactory safety margin. It has been suggested that this ratio should be at least 0.25 (Craus and Livneh 1978; Kanellaidis and Dimitropoulos 1995). Criterion 4: The 'hands-off' speed defined as the threshold speed between positive and negative side friction is an important parameter regarding the safety and comfort of slower drivers. British guidelines (Highway Link Design 1984) require that the hands-off speed should be at most equal to the predicted 15th percentile free speed; the ratio of that speed to the design speed is estimated at around The limiting condition for this criterion is specified by applying a superelevation rate such that the ratio of [ e / (e + f) ] equals 0.36 since (e + f) is proportional to the square power of design speed (Vd)2. Therefore the criterion is satisfied for [ e / (e + f) < If the above criteria are applied for a certain speed environment (which determines the maximum f value) then in the corresponding radius superelevation graph (R e graph) there is an area within which all four criteria are satisfied. Within this area it is possible to define a simple R e relationship by which each allowable radius value corresponds to one single superelevation rate. The paper's proposal specifies possible R e relationships for speed environments between 60 km/h and 120 km/h (in increments of 10 km/h). Figure 1 Figure 2 Figure 3 and Figure 4 illustrate the application of the four criteria as well as the proposed relationships for the speed environments of 60 km/ h 80 km/h 100 km/h and 120 km/h. The proposed relationships consist of linear segments linking rounded pairs of values (usually with an accuracy of 50 or 100 metres for radius and 0.01 for superelevation) intended to provide a practical proposal. Figure 5 presents an overview of the proposal for the range of speed environments examined. It is noted that for speed environments of 100 km/h and above there are no pairs of R e values with e > 0.06 satisfying all four criteria. Therefore for those speed environments the upper parts of the graphs (shown in dotted lines) are replaced by the limiting values of Criterion 2 (maximum f value); for these values Criterion 4 (maximum 'hands-off speed') is not satisfied. It may thus be recommended to avoid superelevation rates exceeding 0.06 for speed

7 Superelevation rate (m /m) Criterion 2 Criterion 4 ; Criterion 3 s s Curve radius (m) Figure 1 Proposed R-e relationship for the speed environment of 60 km/h 0.08 II 1 k Superelevation rate (m/m) Criterion 4 i ' 4 ` II Criterion 3 s s Criterion 4 N. It Curve radius (m) Figure 2 Proposed R-e relationship for the speed environment of 80 km/h

8 Superelevation rate (m/m) Cnterion Criterion 2 Cnterion Curve radius (m) Figure 3 Proposed R-e relationship for the speed environment of 100 km/h Superelevation rate (m/m) Criterion Criterion 2 Criterion (X) (i) Curve radius (m) Figure 4 Proposed R-e relationship for the speed environment of 120 km/h

9 007 1.* 006 E re 008 o 005 ca as c MI = i t I t i I t II I I I I I I I I I I I I I t I I _aa Figure 5 Proposed R-e relationships for speed environments between 60 km/h and 120 km/h Curve Radius (m) Road curve superelevation design: current practices and proposed approach

10 36 environments of 100 km/h and above in order to provide increased comfort and safety for the slowermoving traffic. SUMMARY AND FURTHER ISSUES The Australian highway design guidelines (Austroads 1993) include certain provisions for improving the safety of horizontal curve design. In contrast to US guidelines (AASHTO 1994) where the traditional design-speed approach is utilised Australian standards include four distinct speed parameters: desired speed speed environment design speed and limiting curve speed standard. Thus the two-way interaction between curve geometry and operating speed is acknowledged and trial alignments are used in order to ensure the highest possible degree of horizontal alignment consistency. However the absence of a nationwide maximum superelevation value in combination with designers' freedom (within the consistency constraints specified) to use 'above-minimum' curve radii with a corresponding reduction in superelevation rate and side friction factor may lead to cases where identical curves (with equal radius and superelevation values) correspond to different assumed speeds. Since the curve radius has been proven to be the key determinant of actual operating speeds it is advisable to design curves in such a way that curve radius can be a signal for the total centrifugal acceleration to be expected by the 85th percentile driver; this canbe achieved by more closely linking curvature and superelevation in design practice. This paper has presented a proposal for narrowing down the theoretically infinite choices of aboveminimum curve radii and corresponding superelevation rates. To that end the following criteria are used: (1) a nationwide range of possible superelevation rates between 0.02 and 0.08; (2) a maximum side friction factor depending on the speed environment as specified in Australian guidelines; (3) superelevation rate such as to counter at least one-quarter of the total centrifugal acceleration (safety margin); (4) 'hands-off speed' not exceeding 60 per cent of the speed environment value (provision for the safety and comfort of slower drivers). Criteria (3) and (4) serve to introduce additional safety elements in curve superelevation design going one step further than the Australian guidelines' already substantial existing safeguards of minimum design values and consistency checks. Application of the criteria can be the first step towards applying one-to-one relationships between radius and superelevation for various speed environments. This paper's proposal uses pairs of rounded values leading to simple and straightforward relationships. It also ensures with the exception of a few cases corresponding to maximum or minimum superelevation rates that a specific pair of radius superelevation values corresponds to one single speed environment. The proposed approach is a step towards further enhancing horizontal alignment consistency and as such can be generally beneficial to driver comfort and safety. Driving behaviour variability implies of course that perception of the 'feedback' from the design would be stronger for some drivers and subtler for others. The above criteria or nationally-defined variants taking into account the different national approaches could be adapted to the horizontal curve design procedures of other countries too. At a next stage the approach could be extended to also cover very flat curves (determination of the threshold for removing adverse superelevation). One possible area for further improvement that is not addressed by this paper's proposal concerns the fact that f values acceptable by the 85th percentile driver tend to exceed the design values (especially for speed environments below 90 km/h). Since the application of higher superelevation rates (0.10 or greater) is generally not recommended the question to be posed is whether it would be feasible to raise the design values for f in order to achieve a better matching between design and operating speeds. Considering that the vector of tyre pavement friction on horizontal curves has a tangential and a lateral component any increase in the allowable side friction value (lateral component) will mean a decrease in the available tangential friction coefficient. Therefore if side friction factors were to be increased the consequences with respect to stopping (that is a

11 37 reduction of available tangential friction factor leading to an increase in required stopping sight distance) should be taken into account and weighed against whatever benefits would arise from matching design speed and operating speed. Since tyre pavement friction inventories often reveal large disparities the choice of f values is by necessity conservative; in the longer term improved quality and consistency in both pavement and tyre quality may lead to increased design f values which may correspond more closely to acceptablef values than is the case today. REFERENCES AASHTO (1994). A Policy on Geometric Design of Highways and Streets American Association of State Highway and Transportation Officials (AASHTO) Washington D.C. ANDERSON I.B. and KRAMMES R.A. (1994). Speed Eduction as a Surrogate for Accident Experience at Horizontal Curves on Rural Two-Lane Highways 73rd Annual Meeting of the Transportation Research Board Washington D.C. AUSTROADS (1993). Rural Road Design Guide to the Geometric Design of Rural Roads Austroads Sydney. CRAUS J. and LIVNEH M. (1978). Superelevation and Curvature of Horizontal Curves Transportation Research Record 685 pp TRB National Research Council Washington D.C. ERSF (EUROPEAN ROAD SAFETY FEDERATION) (1996). Intersafe Technical Guide on Road Safety forinterurban Roads ERSF Brussels. GAMBARD J.M. and LOUAH G. (1986). Free Speed as a Function of Road Geometrical Characteristics 14th PTRC Annual Meeting Brighton United Kingdom. HARWOOD D.W. and MASON J.M. Jr. (1994). Horizontal Curve Design for Passenger Cars and Trucks 73rd Annual Meeting of the Transportation Research Board Washington D.C. HAYWARD J. (1980). Highway Alignment and Superelevation: Some Design Speed Misconceptions Transportation Research Record 757 pp TRB National Research Council Washington D.C. HIGHWAY LINK DESIGN (1984) Departmental Advice Note TA 43/84 Department of Transport London United Kingdom. KANELLAIDIS G. (1991). Aspects of Highway Superelevation Design Journal oftransportation Engineering Vol. 117 No. 6 pp American Society of Civil Engineers. KANELLAIDIS G. (1996). Human Factors in Highway Geometric Design Journal of Transportation Engineering Vol. 122 No. 1 pp American Society of Civil Engineers. KANELLAIDIS G. and DIMITROPOULOS I. (1995). Investigation of Current and Proposed Superelevation Design Practices on Roadway Curves TRB International Symposium on Highway Geometric Design Practices Boston Mass. KANELLAIDIS G. GOLIAS J. and EFSTATHIADIS S. (1990). Drivers' Speed Behaviour on Rural Road Curves Traffic Engineering and Control Vol. 31 No. 7 pp KOEPPEL G. (1986). Strassenentwurf Rueckblick und Ausblick Strasse und Autobahn No. 9 pp Federal Republic of Germany (in German). KRAMMES R.A. (1994). Design Speed and Operating Speed in Rural Highway Alignment Design 73rd Annual Meeting of the Transportation Research Board Washington D.C. KRAMMES R.A. and GARNHAM M.A. (1995). Review of Alignment Design Policies Worldwide TRB International Symposium on Highway Geometric Design Practices Boston Mass. LAMM R. CHOUEIRI E. and MAILAENDER T. (1989). Side Friction Demand Versus Side Friction Assumed for Curve Design on Two-Lane Rural Highways Transportation Research Record 1303 pp TRB National Research Council Washington D.C. LAMM R. GUENTHER A. K. and CHOUEIRI E.M. (1992). Safety Module for Highway Design: Applied Manually or Using CAD 71st Annual Meeting of the Transportation Research Board Washington D.C. LEISCH J.E. and LEISCH J.P. (1977). New Concepts in Design Speed Application Transportation Research Record 631 pp TRB National Research Council Washington D.C. McLEAN J.R. (1981). Driver Speed Behaviour and Rural Road Alignment Design Traffic Engineering and Control No. 4 pp MESSER C.J. MOUNCE J.M. and BRACKETT R.Q. (1981). Highway Geometric Design Consistency Related to Driver Expectancy Vols. II and III Federal Highway Administration Washington D.C. NICHOLSON A. (1998). Superelevation Side Friction and Roadway Consistency Journal of Transportation Engineering Vol. 124 No. 5 pp American Society of Civil Engineers. OTTESEN J.L. and KRAMMES R.A. (1994). Speed Profile Model for a US Operating-Speed-Based Design Consistency Evaluation Procedure 73rd Annual Meeting of the Transportation Research Board Washington D.C. TARAGIN A. (1954). Driver Performance on Horizontal Curves Proceedings of the Thirty-Third Annual Meeting of the Highway Research Board pp TRB National Research Council Washington D.C.

12 38 George Kanellaidis is a Civil and Transportation Engineer with more than 25 years of expertise in a large number of Greek and international projects and research in the field of highway engineering human factors and road safety. His current position is Associate Professor in the Department of Transportation Planning and Engineering at the National Technical University of Athens. Contact Dr George Kanellaidis National Technical University of Athens Department of Transportation Planning and Engineering Iroon Polytechniou Zografou / Athens Greece Tel Fax g-kanel@central.ntua.gr

Recommendations for AASHTO Superelevation Design

Recommendations for AASHTO Superelevation Design Recommendations for AASHTO Superelevation Design September, 2003 Prepared by: Design Quality Assurance Bureau NYSDOT TABLE OF CONTENTS Contents Page INTRODUCTION...1 OVERVIEW AND COMPARISON...1 Fundamentals...1

More information

Geometric Design Guidelines to Achieve Desired Operating Speed on Urban Streets

Geometric Design Guidelines to Achieve Desired Operating Speed on Urban Streets Geometric Design Guidelines to Achieve Desired Operating Speed on Urban Streets Christopher M. Poea and John M. Mason, Jr.b INTRODUCTION Speed control is often cited as a critical issue on urban collector

More information

A KINEMATIC APPROACH TO HORIZONTAL CURVE TRANSITION DESIGN. James A. Bonneson, P.E.

A KINEMATIC APPROACH TO HORIZONTAL CURVE TRANSITION DESIGN. James A. Bonneson, P.E. TRB Paper No.: 00-0590 A KINEMATIC APPROACH TO HORIZONTAL CURVE TRANSITION DESIGN by James A. Bonneson, P.E. Associate Research Engineer Texas A&M University College Station, TX 77843-3135 (409) 845-9906

More information

Horizontal Curve Design for Passenger

Horizontal Curve Design for Passenger 22 TRANSPOR'TATION RESEARCH RECORD 1445 Horizontal Curve Design for Passenger Cars and Trucks DOUGLAS W. HARWOOD AND ]OHN M. MASON, ]R. The adequacy of the 1990 AASHTO geometric design policy for safely

More information

DESIGN SPEED CHOICES FOR CANADIAN TWO-LANE RURAL HIGHWAYS. Dr. John F. Morrall, P.Eng. President Canadian Highways Institute Ltd.

DESIGN SPEED CHOICES FOR CANADIAN TWO-LANE RURAL HIGHWAYS. Dr. John F. Morrall, P.Eng. President Canadian Highways Institute Ltd. DESIGN SPEED CHOICES FOR CANADIAN TWO-LANE RURAL HIGHWAYS Dr. John F. Morrall, P.Eng. President Canadian Highways Institute Ltd. Calgary, Alberta Dr. John B. L. Robinson, P.Eng. Chief Road Safety Engineer

More information

GEOMETRIC ALIGNMENT AND DESIGN

GEOMETRIC ALIGNMENT AND DESIGN GEOMETRIC ALIGNMENT AND DESIGN Geometric parameters dependent on design speed For given design speeds, designers aim to achieve at least the desirable minimum values for stopping sight distance, horizontal

More information

A review of design speed based on observed behaviour

A review of design speed based on observed behaviour A review of design speed based on observed behaviour Zita Langenbach Arup Paul Lewis NUI Maynooth NUIM Research Team Tim McCarthy Lars Pforte Paul Lewis What is Design Speed? The speed which determines

More information

Sight Distance. A fundamental principle of good design is that

Sight Distance. A fundamental principle of good design is that Session 9 Jack Broz, PE, HR Green May 5-7, 2010 Sight Distance A fundamental principle of good design is that the alignment and cross section should provide adequate sight lines for drivers operating their

More information

ACCIDENT MODIFICATION FACTORS FOR MEDIAN WIDTH

ACCIDENT MODIFICATION FACTORS FOR MEDIAN WIDTH APPENDIX G ACCIDENT MODIFICATION FACTORS FOR MEDIAN WIDTH INTRODUCTION Studies on the effect of median width have shown that increasing width reduces crossmedian crashes, but the amount of reduction varies

More information

LESSON Transmission of Power Introduction

LESSON Transmission of Power Introduction LESSON 3 3.0 Transmission of Power 3.0.1 Introduction Earlier in our previous course units in Agricultural and Biosystems Engineering, we introduced ourselves to the concept of support and process systems

More information

Horizontal Alignment

Horizontal Alignment Session 8 Jim Rosenow, PE, Mn/DOT March 5-7, 2010 Horizontal Alignment The shortest distance between two points is: A straight line The circumference of a circle passing through both points and the center

More information

Improvement of Vehicle Dynamics by Right-and-Left Torque Vectoring System in Various Drivetrains x

Improvement of Vehicle Dynamics by Right-and-Left Torque Vectoring System in Various Drivetrains x Improvement of Vehicle Dynamics by Right-and-Left Torque Vectoring System in Various Drivetrains x Kaoru SAWASE* Yuichi USHIRODA* Abstract This paper describes the verification by calculation of vehicle

More information

GARCÍA et al., NEW CONSISTENCY INDEX BASED ON INERTIAL OPERATING SPEED

GARCÍA et al., NEW CONSISTENCY INDEX BASED ON INERTIAL OPERATING SPEED GARCÍA et al., 0 0 0 0 NEW CONSISTENCY INDEX BASED ON INERTIAL OPERATING SPEED Corresponding Author: Alfredo García Professor Highway Engineering Research Group, Universitat Politècnica de València Camino

More information

Side Friction. Demanded and Margins of Safety on Horizontal Curves

Side Friction. Demanded and Margins of Safety on Horizontal Curves TRANSPORTATION RESEARCH RECORD 1435 145 Side Friction. Demanded and Margins of Safety on Horizontal Curves J. F. MORRALL AND R. J. TALARICO The findings of a research project that was conducted to determine

More information

DRIVER SPEED COMPLIANCE WITHIN SCHOOL ZONES AND EFFECTS OF 40 PAINTED SPEED LIMIT ON DRIVER SPEED BEHAVIOURS Tony Radalj Main Roads Western Australia

DRIVER SPEED COMPLIANCE WITHIN SCHOOL ZONES AND EFFECTS OF 40 PAINTED SPEED LIMIT ON DRIVER SPEED BEHAVIOURS Tony Radalj Main Roads Western Australia DRIVER SPEED COMPLIANCE WITHIN SCHOOL ZONES AND EFFECTS OF 4 PAINTED SPEED LIMIT ON DRIVER SPEED BEHAVIOURS Tony Radalj Main Roads Western Australia ABSTRACT Two speed surveys were conducted on nineteen

More information

SUMMARY OF THE IMPACT ASSESSMENT

SUMMARY OF THE IMPACT ASSESSMENT COMMISSION OF THE EUROPEAN COMMUNITIES Brussels, 13.11.2008 SEC(2008) 2861 COMMISSION STAFF WORKING DOCUMT Accompanying document to the Proposal for a DIRECTIVE OF THE EUROPEAN PARLIAMT AND OF THE COUNCIL

More information

Identification of safety hazards on existing road network regarding road Geometric Design: Implementation in Greece

Identification of safety hazards on existing road network regarding road Geometric Design: Implementation in Greece 4 th International Conference on Road Safety and Simulation RSS 2013 23 rd -25 th October 2013 Rome, Italy Identification of safety hazards on existing road network regarding road Geometric Design: Implementation

More information

New Consistency Index Based on Inertial Operating Speed

New Consistency Index Based on Inertial Operating Speed New Consistency Index Based on Inertial Operating Speed Alfredo García, David Llopis-Castelló, Francisco Javier Camacho-Torregrosa, and Ana María Pérez-Zuriaga The occurrence of road crashes depends on

More information

Free-Flow Speed Model Based on Portuguese Roadway Design Features for Two-Lane Highways

Free-Flow Speed Model Based on Portuguese Roadway Design Features for Two-Lane Highways Free-Flow Speed Model Based on Portuguese Roadway Design Features for Two-Lane Highways António Lobo, Carlos Rodrigues, and António Couto Speed is a key performance measure in economic and environmental

More information

Driveway Spacing and Traffic Operations

Driveway Spacing and Traffic Operations Driveway Spacing and Traffic Operations ABSTRACT JEROME S. GLUCK, GREG HAAS, JAMAL MAHMOOD Urbitran Associates 71 West 23rd Street, 11th Floor New York, NY 10010 urbitran@ix.netcom.com HERBERT S. LEVINSON

More information

Maximum Superelevation: Desirable, Allowable, and Absolute

Maximum Superelevation: Desirable, Allowable, and Absolute Maximum Superelevation: Desirable, Allowable, and Absolute Nazmul Hasan, M. Eng. SNC-Lavalin Inc. ancouver, ON ABSTRACT The maximum values of superelevation are often qualified as desirable, allowable

More information

Use of Flow Network Modeling for the Design of an Intricate Cooling Manifold

Use of Flow Network Modeling for the Design of an Intricate Cooling Manifold Use of Flow Network Modeling for the Design of an Intricate Cooling Manifold Neeta Verma Teradyne, Inc. 880 Fox Lane San Jose, CA 94086 neeta.verma@teradyne.com ABSTRACT The automatic test equipment designed

More information

ASEP Development Strategy for ASEP Revision 2 Development of a Physical Expectation Model Based on UN R51.03 Annex 3 Performance Parameters

ASEP Development Strategy for ASEP Revision 2 Development of a Physical Expectation Model Based on UN R51.03 Annex 3 Performance Parameters July 2017 P R E S E N T A T I O N O F INTERNATIONAL ORGANIZATION OF MOTOR VEHICLE MANUFACTURERS ASEP Development Strategy for ASEP Revision 2 Development of a Physical Expectation Model Based on UN R51.03

More information

Conventional Approach

Conventional Approach Session 6 Jack Broz, PE, HR Green May 5-7, 2010 Conventional Approach Classification required by Federal law General Categories: Arterial Collector Local 6-1 Functional Classifications Changing Road Classification

More information

Horizontal Sight Distance Considerations Freeway and Interchange Reconstruction

Horizontal Sight Distance Considerations Freeway and Interchange Reconstruction 80 TRANSPORTATION RESEARCH RECORD 1208 Horizontal Sight Distance Considerations Freeway and Interchange Reconstruction In JOEL p. LEISCH With improvements being made to freeways and expressways, the problem

More information

Chapter III Geometric design of Highways. Tewodros N.

Chapter III Geometric design of Highways. Tewodros N. Chapter III Geometric design of Highways Tewodros N. www.tnigatu.wordpress.com tedynihe@gmail.com Introduction Appropriate Geometric Standards Design Controls and Criteria Design Class Sight Distance Design

More information

GEOMETRIC ALIGNMENT AND DESIGN

GEOMETRIC ALIGNMENT AND DESIGN GEOMETRIC ALIGNMENT AND DESIGN Geometric parameters dependent on design speed For given design speeds, designers aim to achieve at least the desirable minimum values for stopping sight distance, horizontal

More information

A study of the minimum safe stopping distance between vehicles in terms of braking systems, weather and pavement conditions

A study of the minimum safe stopping distance between vehicles in terms of braking systems, weather and pavement conditions A study of the minimum safe stopping distance between vehicles in terms of braking systems, weather and pavement conditions Mansour Hadji Hosseinlou 1 ; Hadi Ahadi 2 and Vahid Hematian 3 Transportation

More information

EVALUATING THE SAFETY RISK OF NARROW MEDIANS AND RESTRICTED SIGHT DISTANCE. Laurel Richl, University of British Columbia

EVALUATING THE SAFETY RISK OF NARROW MEDIANS AND RESTRICTED SIGHT DISTANCE. Laurel Richl, University of British Columbia EVALUATING THE SAFETY RISK OF NARROW MEDIANS AND RESTRICTED SIGHT DISTANCE Laurel Richl, University of British Columbia Tarek Sayed, University of British Columbia Paper prepared for presentation at the

More information

Chapter III Geometric design of Highways. Tewodros N.

Chapter III Geometric design of Highways. Tewodros N. Chapter III Geometric design of Highways Tewodros N. www.tnigatu.wordpress.com tedynihe@gmail.com Introduction Appropriate Geometric Standards Design Controls and Criteria Design Class Sight Distance Design

More information

Analyzing Crash Risk Using Automatic Traffic Recorder Speed Data

Analyzing Crash Risk Using Automatic Traffic Recorder Speed Data Analyzing Crash Risk Using Automatic Traffic Recorder Speed Data Thomas B. Stout Center for Transportation Research and Education Iowa State University 2901 S. Loop Drive Ames, IA 50010 stouttom@iastate.edu

More information

Understanding design, operating, and posted speed

Understanding design, operating, and posted speed Understanding design, operating, and posted speed Report No. 1465-1 Sponsored by Texas Department of Transportation in cooperation with U.S. Department of Transportation Federal Highway Administration

More information

Developing a Framework for Evaluating and Selecting Curve Safety Treatments. Srinivas R. Geedipally, Ph.D., P.E.

Developing a Framework for Evaluating and Selecting Curve Safety Treatments. Srinivas R. Geedipally, Ph.D., P.E. 0 0 0 Paper No.: -0 Developing a Framework for Evaluating and Selecting Curve Safety Treatments By: Michael P. Pratt, P.E. (corresponding author) Assistant Research Engineer Texas A&M Transportation Institute

More information

MPC-574 July 3, University University of Wyoming

MPC-574 July 3, University University of Wyoming MPC-574 July 3, 2018 Project Title Proposing New Speed Limit in Mountainous Areas Considering the Effect of Longitudinal Grades, Vehicle Characteristics, and the Weather Condition University University

More information

Effect of Police Control on U-turn Saturation Flow at Different Median Widths

Effect of Police Control on U-turn Saturation Flow at Different Median Widths Effect of Police Control on U-turn Saturation Flow at Different Widths Thakonlaphat JENJIWATTANAKUL 1 and Kazushi SANO 2 1 Graduate Student, Dept. of Civil and Environmental Eng., Nagaoka University of

More information

Acceleration Behavior of Drivers in a Platoon

Acceleration Behavior of Drivers in a Platoon University of Iowa Iowa Research Online Driving Assessment Conference 2001 Driving Assessment Conference Aug 1th, :00 AM Acceleration Behavior of Drivers in a Platoon Ghulam H. Bham University of Illinois

More information

GPS Vehicle Tracking in Urban Areas

GPS Vehicle Tracking in Urban Areas Paper 139 GPS Vehicle Tracking in Urban Areas Civil-Comp Press, 2012 Proceedings of the Eighth International Conference on Engineering Computational Technology, B.H.V. Topping, (Editor), Civil-Comp Press,

More information

GEOMETRIC PARAMETERS Affecting Capacity ICD 2

GEOMETRIC PARAMETERS Affecting Capacity ICD 2 Single Lane Roundabouts Geometric Design in Context -Urban versus Rural 1 GEOMETRIC PARAMETERS Affecting Capacity ICD 2 Effective Geometry V = Approach Road half width 3 E = Entry Width L = Effective Flare

More information

AP-R211 GEOMETRIC DESIGN FOR TRUCKS WHEN, WHERE AND HOW? A USTROADS

AP-R211 GEOMETRIC DESIGN FOR TRUCKS WHEN, WHERE AND HOW? A USTROADS AP-R211 GEOMETRIC DESIGN FOR TRUCKS WHEN, WHERE AND HOW? A USTROADS First Published 2002 Austroads Inc. 2002 This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part

More information

Featured Articles Utilization of AI in the Railway Sector Case Study of Energy Efficiency in Railway Operations

Featured Articles Utilization of AI in the Railway Sector Case Study of Energy Efficiency in Railway Operations 128 Hitachi Review Vol. 65 (2016), No. 6 Featured Articles Utilization of AI in the Railway Sector Case Study of Energy Efficiency in Railway Operations Ryo Furutani Fumiya Kudo Norihiko Moriwaki, Ph.D.

More information

Research on Skid Control of Small Electric Vehicle (Effect of Velocity Prediction by Observer System)

Research on Skid Control of Small Electric Vehicle (Effect of Velocity Prediction by Observer System) Proc. Schl. Eng. Tokai Univ., Ser. E (17) 15-1 Proc. Schl. Eng. Tokai Univ., Ser. E (17) - Research on Skid Control of Small Electric Vehicle (Effect of Prediction by Observer System) by Sean RITHY *1

More information

THE INFLUENCE OF VISIBILITY CONDITIONS IN HORIZONTAL ROAD CURVES ON THE EFFICIENCY OF NOISE PROTECTION BARRIERS

THE INFLUENCE OF VISIBILITY CONDITIONS IN HORIZONTAL ROAD CURVES ON THE EFFICIENCY OF NOISE PROTECTION BARRIERS DOI: 10.1515/rjti-2015-0016 ROMANIAN JOURNAL THE INFLUENCE OF VISIBILITY CONDITIONS IN HORIZONTAL ROAD CURVES ON THE EFFICIENCY OF NOISE PROTECTION BARRIERS Tamara Džambas, Assistant, MCE, University of

More information

Geometric Design Consistency and its relation Tosafety on Outer Ring Road

Geometric Design Consistency and its relation Tosafety on Outer Ring Road Geometric Design Consistency and its relation Tosafety on Outer Ring Road D.Rajashekar Reddy 1, K.Shashidher 2 1 Associate professor, 2 M.E Student Civil Engineering department, University College of Engineering,

More information

THE ACCELERATION OF LIGHT VEHICLES

THE ACCELERATION OF LIGHT VEHICLES THE ACCELERATION OF LIGHT VEHICLES CJ BESTER AND GF GROBLER Department of Civil Engineering, University of Stellenbosch, Private Bag X1, MATIELAND 7602 Tel: 021 808 4377, Fax: 021 808 4440 Email: cjb4@sun.ac.za

More information

Devices to Assist Drivers to Comply with Speed Limits

Devices to Assist Drivers to Comply with Speed Limits Vehicle Design and Research Pty Limited Australian Business No. 63 003 980 809 mpaineattpg.com.au Devices to Assist Drivers to Comply with Speed Limits Prepared by Michael Paine, Manager, Vehilce Design

More information

AASHTO Policy on Geometric Design of Highways and Streets

AASHTO Policy on Geometric Design of Highways and Streets AASHTO Policy on Geometric Design of Highways and Streets 2001 Highlights and Major Changes Since the 1994 Edition Jim Mills, P.E. Roadway Design Office 605 Suwannee Street MS-32 Tallahassee, FL 32399-0450

More information

(Refer Slide Time: 00:01:10min)

(Refer Slide Time: 00:01:10min) Introduction to Transportation Engineering Dr. Bhargab Maitra Department of Civil Engineering Indian Institute of Technology, Kharagpur Lecture - 11 Overtaking, Intermediate and Headlight Sight Distances

More information

CEE 320. Fall Horizontal Alignment

CEE 320. Fall Horizontal Alignment Horizontal Alignment Horizontal Alignment Objective: Geometry of directional transition to ensure: Safety Comfort Primary challenge Transition between two directions Fundamentals Circular curves Superelevation

More information

A REVIEW OF THE EFFECT OF INCREASES IN VEHICLE SIZE ON AUSTRALIAN GEOMETRIC ROAD DESIGN STANDARDS

A REVIEW OF THE EFFECT OF INCREASES IN VEHICLE SIZE ON AUSTRALIAN GEOMETRIC ROAD DESIGN STANDARDS Pages 252-277 A REVIEW OF THE EFFECT OF INCREASES IN VEHICLE SIZE ON AUSTRALIAN GEOMETRIC ROAD DESIGN STANDARDS Ricky Cox Transport Technology Division Queensland Department of Main Roads GPO Box 1412

More information

FRONTAL OFF SET COLLISION

FRONTAL OFF SET COLLISION FRONTAL OFF SET COLLISION MARC1 SOLUTIONS Rudy Limpert Short Paper PCB2 2014 www.pcbrakeinc.com 1 1.0. Introduction A crash-test-on- paper is an analysis using the forward method where impact conditions

More information

inter.noise 2000 The 29th International Congress and Exhibition on Noise Control Engineering August 2000, Nice, FRANCE

inter.noise 2000 The 29th International Congress and Exhibition on Noise Control Engineering August 2000, Nice, FRANCE Copyright SFA - InterNoise 2000 1 inter.noise 2000 The 29th International Congress and Exhibition on Noise Control Engineering 27-30 August 2000, Nice, FRANCE I-INCE Classification: 0.0 EFFECTS OF TRANSVERSE

More information

Technical Report Documentation Page. 1. Report No. 2. Government Accession No. FHW A/TX-95/1465-2F. 3. Recipient's Catalog No.

Technical Report Documentation Page. 1. Report No. 2. Government Accession No. FHW A/TX-95/1465-2F. 3. Recipient's Catalog No. Technical Report Documentation Page 1. Report No. 2. Government Accession No. FHW A/TX-95/1465-2F 4. Title and Subtitle COMPATIBILITY OF DESIGN SPEED, OPERATING SPEED, AND POSTED SPEED 7. Author(s) Kay

More information

Driving Tests: Reliability and the Relationship Between Test Errors and Accidents

Driving Tests: Reliability and the Relationship Between Test Errors and Accidents University of Iowa Iowa Research Online Driving Assessment Conference 2001 Driving Assessment Conference Aug 16th, 12:00 AM Driving Tests: Reliability and the Relationship Between Test Errors and Accidents

More information

Measurement methods for skid resistance of road surfaces

Measurement methods for skid resistance of road surfaces Measurement methods for skid resistance of road surfaces Presented by Martin Greene (TRL) and Veronique Cerezo (IFSTTAR) 11 October 2016 Background and requirements for Common Scale 1 Background Measurement

More information

Modelling and Analysis of Crash Densities for Karangahake Gorge, New Zealand

Modelling and Analysis of Crash Densities for Karangahake Gorge, New Zealand Modelling and Analysis of Crash Densities for Karangahake Gorge, New Zealand Cenek, P.D. & Davies, R.B. Opus International Consultants; Statistics Research Associates Limited ABSTRACT An 18 km length of

More information

Low Speed Design Criteria for Residential Streets Andrew J. Ballard, P.E. and David M. Haldeman, E.I.T.

Low Speed Design Criteria for Residential Streets Andrew J. Ballard, P.E. and David M. Haldeman, E.I.T. Low Speed Design Criteria for Residential Streets Andrew J. Ballard, P.E. and David M. Haldeman, E.I.T. Background The City of San Antonio receives many complaints regarding speeding in residential areas.

More information

Lecture 4: Capacity and Level of Service (LoS) of Freeways Basic Segments. Prof. Responsável: Filipe Moura

Lecture 4: Capacity and Level of Service (LoS) of Freeways Basic Segments. Prof. Responsável: Filipe Moura Lecture 4: Capacity and Level of Service (LoS) of Freeways Basic Segments Prof. Responsável: Filipe Moura Engenharia de Tráfego Rodoviário Lecture 4 - Basic Freeway segments 1 CAPACITY AND LEVEL OF SERVICE

More information

Models of Driver Speed Choice in Curves

Models of Driver Speed Choice in Curves AVEC 4 Models of Driver Speed Choice in Curves Andrew MC Odhams and David J Cole Cambridge University Engineering Department Trumpington Street, Cambridge, CB 1PZ, UK Phone +44 ()13 336 Fax +44 ()13 33

More information

Driver Speed Compliance in Western Australia. Tony Radalj and Brian Kidd Main Roads Western Australia

Driver Speed Compliance in Western Australia. Tony Radalj and Brian Kidd Main Roads Western Australia Driver Speed Compliance in Western Australia Abstract Tony Radalj and Brian Kidd Main Roads Western Australia A state-wide speed survey was conducted over the period March to June 2 to measure driver speed

More information

JCE4600 Fundamentals of Traffic Engineering

JCE4600 Fundamentals of Traffic Engineering JCE4600 Fundamentals of Traffic Engineering Introduction to Geometric Design Agenda Kinematics Human Factors Stopping Sight Distance Cornering Intersection Design Cross Sections 1 AASHTO Green Book Kinematics

More information

An Evaluation of the Relationship between the Seat Belt Usage Rates of Front Seat Occupants and Their Drivers

An Evaluation of the Relationship between the Seat Belt Usage Rates of Front Seat Occupants and Their Drivers An Evaluation of the Relationship between the Seat Belt Usage Rates of Front Seat Occupants and Their Drivers Vinod Vasudevan Transportation Research Center University of Nevada, Las Vegas 4505 S. Maryland

More information

Innovative Power Supply System for Regenerative Trains

Innovative Power Supply System for Regenerative Trains Innovative Power Supply System for Regenerative Trains Takafumi KOSEKI 1, Yuruki OKADA 2, Yuzuru YONEHATA 3, SatoruSONE 4 12 The University of Tokyo, Japan 3 Mitsubishi Electric Corp., Japan 4 Kogakuin

More information

Approach for determining WLTPbased targets for the EU CO 2 Regulation for Light Duty Vehicles

Approach for determining WLTPbased targets for the EU CO 2 Regulation for Light Duty Vehicles Approach for determining WLTPbased targets for the EU CO 2 Regulation for Light Duty Vehicles Brussels, 17 May 2013 richard.smokers@tno.nl norbert.ligterink@tno.nl alessandro.marotta@jrc.ec.europa.eu Summary

More information

EUROPEAN COMMISSION ENTERPRISE AND INDUSTRY DIRECTORATE-GENERAL

EUROPEAN COMMISSION ENTERPRISE AND INDUSTRY DIRECTORATE-GENERAL EUROPEAN COMMISSION ENTERPRISE AND INDUSTRY DIRECTORATE-GENERAL Consumer Goods and EU Satellite navigation programmes Automotive industry Brussels, 08 April 2010 ENTR.F1/KS D(2010) European feed back to

More information

Examining the load peaks in high-speed railway transport

Examining the load peaks in high-speed railway transport Examining the load peaks in high-speed railway transport Yigit Fidansoy, M.Sc. Technische Universität Darmstadt, Germany fidansoy@verkehr.tu-darmstadt.de Paper prepared for DEMAND Centre Conference, Lancaster,

More information

HOW MUCH DRIVING DATA DO WE NEED TO ASSESS DRIVER BEHAVIOR?

HOW MUCH DRIVING DATA DO WE NEED TO ASSESS DRIVER BEHAVIOR? 0 0 0 0 HOW MUCH DRIVING DATA DO WE NEED TO ASSESS DRIVER BEHAVIOR? Extended Abstract Anna-Maria Stavrakaki* Civil & Transportation Engineer Iroon Polytechniou Str, Zografou Campus, Athens Greece Tel:

More information

TURN AND CURVE SIGNS

TURN AND CURVE SIGNS Page 1 of 6 RECOMMENDED PRACTICES PART SECTION SUB-SECTION HIGHWAY SIGNS WARNING SIGNS General Standard Unexpected changes in roadway alignment (such as abrupt turns, curves, or the termination of road

More information

CRASH RISK RELATIONSHIPS FOR IMPROVED SAFETY MANAGEMENT OF ROADS

CRASH RISK RELATIONSHIPS FOR IMPROVED SAFETY MANAGEMENT OF ROADS CRASH RISK RELATIONSHIPS FOR IMPROVED SAFETY MANAGEMENT OF ROADS Cenek, P.D. 1 & Davies, R.B. 2 1 Opus International Consultants 2 Statistics Research Associates ABSTRACT This paper presents the results

More information

Simulation of Collective Load Data for Integrated Design and Testing of Vehicle Transmissions. Andreas Schmidt, Audi AG, May 22, 2014

Simulation of Collective Load Data for Integrated Design and Testing of Vehicle Transmissions. Andreas Schmidt, Audi AG, May 22, 2014 Simulation of Collective Load Data for Integrated Design and Testing of Vehicle Transmissions Andreas Schmidt, Audi AG, May 22, 2014 Content Introduction Usage of collective load data in the development

More information

CHAPTER 9: VEHICULAR ACCESS CONTROL Introduction and Goals Administration Standards

CHAPTER 9: VEHICULAR ACCESS CONTROL Introduction and Goals Administration Standards 9.00 Introduction and Goals 9.01 Administration 9.02 Standards 9.1 9.00 INTRODUCTION AND GOALS City streets serve two purposes that are often in conflict moving traffic and accessing property. The higher

More information

Traffic Signal Volume Warrants A Delay Perspective

Traffic Signal Volume Warrants A Delay Perspective Traffic Signal Volume Warrants A Delay Perspective The Manual on Uniform Traffic Introduction The 2009 Manual on Uniform Traffic Control Devices (MUTCD) Control Devices (MUTCD) 1 is widely used to help

More information

Alternative Design Consistency Rating Methods for Two-Lane Rural Highways

Alternative Design Consistency Rating Methods for Two-Lane Rural Highways Alternative Design Consistency Rating Methods for Two-Lane Rural Highways PUBLICATION NO. 99-172 AUGUST 2000 Research, Development, and Technology Turner-Fairbank Highway Research Center 6300 Georgetown

More information

Safety Module for Highway Geometric Design

Safety Module for Highway Geometric Design TRANSPORTATION RESEARCH RECORD 1512 7 Safety Module for Highway Geometric Design RUEDIGER LAMM, ARTUR K. GUENTHER, AND ELIAS M. CHOUEIRI Three safety criteria for evaluating curved roadway sections including

More information

Proposal for a DECISION OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL

Proposal for a DECISION OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL EUROPEAN COMMISSION Brussels, 17.5.2018 COM(2018) 275 final 2018/0130 (COD) Proposal for a DECISION OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL amending Council Directive 96/53/EC as regards the time

More information

AN ANALYSIS OF DRIVER S BEHAVIOR AT MERGING SECTION ON TOKYO METOPOLITAN EXPRESSWAY WITH THE VIEWPOINT OF MIXTURE AHS SYSTEM

AN ANALYSIS OF DRIVER S BEHAVIOR AT MERGING SECTION ON TOKYO METOPOLITAN EXPRESSWAY WITH THE VIEWPOINT OF MIXTURE AHS SYSTEM AN ANALYSIS OF DRIVER S BEHAVIOR AT MERGING SECTION ON TOKYO METOPOLITAN EXPRESSWAY WITH THE VIEWPOINT OF MIXTURE AHS SYSTEM Tetsuo Shimizu Department of Civil Engineering, Tokyo Institute of Technology

More information

Support for the revision of the CO 2 Regulation for light duty vehicles

Support for the revision of the CO 2 Regulation for light duty vehicles Support for the revision of the CO 2 Regulation for light duty vehicles and #3 for - No, Maarten Verbeek, Jordy Spreen ICCT-workshop, Brussels, April 27, 2012 Objectives of projects Assist European Commission

More information

Multivariate Operating Speed Forecasting Model Based on the Geometric Elements of Two-Lane Highways

Multivariate Operating Speed Forecasting Model Based on the Geometric Elements of Two-Lane Highways Multivariate Operating Speed Forecasting Model Based on the Geometric Elements of Two-Lane Highways Daniel S. P. Garcia Faculdade de Arquitetura, Universidade Federal do Rio Grande do Sul., Porto Alegre,

More information

Weight Allowance Reduction for Quad-Axle Trailers. CVSE Director Decision

Weight Allowance Reduction for Quad-Axle Trailers. CVSE Director Decision Weight Allowance Reduction for Quad-Axle Trailers CVSE Director Decision Brian Murray February 2014 Contents SYNOPSIS...2 INTRODUCTION...2 HISTORY...3 DISCUSSION...3 SAFETY...4 VEHICLE DYNAMICS...4 LEGISLATION...5

More information

An Analysis of Less Hazardous Roadside Signposts. By Andrei Lozzi & Paul Briozzo Dept of Mechanical & Mechatronic Engineering University of Sydney

An Analysis of Less Hazardous Roadside Signposts. By Andrei Lozzi & Paul Briozzo Dept of Mechanical & Mechatronic Engineering University of Sydney An Analysis of Less Hazardous Roadside Signposts By Andrei Lozzi & Paul Briozzo Dept of Mechanical & Mechatronic Engineering University of Sydney 1 Abstract This work arrives at an overview of requirements

More information

DEVELOPMENT OF A CONTROL MODEL FOR A FOUR WHEEL MECANUM VEHICLE. M. de Villiers 1, Prof. G. Bright 2

DEVELOPMENT OF A CONTROL MODEL FOR A FOUR WHEEL MECANUM VEHICLE. M. de Villiers 1, Prof. G. Bright 2 de Villiers Page 1 of 10 DEVELOPMENT OF A CONTROL MODEL FOR A FOUR WHEEL MECANUM VEHICLE M. de Villiers 1, Prof. G. Bright 2 1 Council for Scientific and Industrial Research Pretoria, South Africa e-mail1:

More information

1.3 Research Objective

1.3 Research Objective 1.3 Research Objective This research project will focus on a solution package that can facilitate the following objectives: 1. A better delineation of the no-passing zone, in particular the danger zone,

More information

Review of the Technical Specifications for the BCFS Intermediate Class Ferry and the provisions of the BC Ferry Commission Order 13-01

Review of the Technical Specifications for the BCFS Intermediate Class Ferry and the provisions of the BC Ferry Commission Order 13-01 BC Ferry Commission First Floor, 1312 Blanshard Street P.O. Box 9279 Victoria, British Columbia V8W 3S2 3GA Marine Ltd 505-827 Fairfield Road Victoria British Columbia V8V 5B2 Review of the Technical Specifications

More information

Background. Request for Decision. Pedestrian Lighting Standards for Road Right-of-ways. Recommendation. Presented: Monday, Mar 17, 2014

Background. Request for Decision. Pedestrian Lighting Standards for Road Right-of-ways. Recommendation. Presented: Monday, Mar 17, 2014 Presented To: Operations Committee Request for Decision Pedestrian Lighting Standards for Road Right-of-ways Presented: Monday, Mar 17, 2014 Report Date Thursday, Mar 06, 2014 Type: Presentations Recommendation

More information

Non-contact Deflection Measurement at High Speed

Non-contact Deflection Measurement at High Speed Non-contact Deflection Measurement at High Speed S.Rasmussen Delft University of Technology Department of Civil Engineering Stevinweg 1 NL-2628 CN Delft The Netherlands J.A.Krarup Greenwood Engineering

More information

PREDICTION OF FUEL CONSUMPTION

PREDICTION OF FUEL CONSUMPTION PREDICTION OF FUEL CONSUMPTION OF AGRICULTURAL TRACTORS S. C. Kim, K. U. Kim, D. C. Kim ABSTRACT. A mathematical model was developed to predict fuel consumption of agricultural tractors using their official

More information

Structural Analysis Of Reciprocating Compressor Manifold

Structural Analysis Of Reciprocating Compressor Manifold Purdue University Purdue e-pubs International Compressor Engineering Conference School of Mechanical Engineering 2016 Structural Analysis Of Reciprocating Compressor Manifold Marcos Giovani Dropa Bortoli

More information

CAUSE ANALYSIS OF TRAFFIC CRASHES BLACK SPOTS ON HIGHWAY LONG STEEP DOWNGRADES IN CHINA

CAUSE ANALYSIS OF TRAFFIC CRASHES BLACK SPOTS ON HIGHWAY LONG STEEP DOWNGRADES IN CHINA CAUSE ANALYSIS OF TRAFFIC CRASHES BLACK SPOTS ON HIGHWAY LONG STEEP DOWNGRADES IN CHINA JIAO Chengwu Research Institute of Highway (RIOH), MoT 8 Xitucheng Rd, Beijing, China E-mail: cw.jiao@rioh.cn HAO

More information

Passing Sight Distance Criteria

Passing Sight Distance Criteria 15-26 Copy No. Passing Sight Distance Criteria Interim Report NCHRP Project 15-26 MRI Project 110348 Prepared for National Cooperative Highway Research Program Transportation Research Board National Research

More information

Guidelines for Retro-fitting Existing Roads to Optimise Safety Benefits. A Practitioners Experience and Assessment of Options for Improvement.

Guidelines for Retro-fitting Existing Roads to Optimise Safety Benefits. A Practitioners Experience and Assessment of Options for Improvement. Guidelines for Retro-fitting Existing Roads to Optimise Safety Benefits. A Practitioners Experience and Assessment of Options for Improvement. Author: Stephen Levett, Manager, Safer Roads Policy, Standards

More information

KENTUCKY TRANSPORTATION CENTER

KENTUCKY TRANSPORTATION CENTER Research Report KTC-06-12/SPR286-05-1F KENTUCKY TRANSPORTATION CENTER ANALYSIS OF INCONSISTENCIES RELATED TO DESIGN SPEED, OPERATING SPEED, AND SPEED LIMITS UNIVERSITY OF KENTUCKY College of Engineering

More information

A comparative analysis of the performance of heavy vehicle combinations from OECD member countries by computer simulation.

A comparative analysis of the performance of heavy vehicle combinations from OECD member countries by computer simulation. A comparative analysis of the performance of heavy vehicle combinations from OECD member countries by computer simulation. Mr. Adam Ritzinger, B Eng (Mech) Mr. Anthony Germanchev, B Eng (Mech) ARRB Group

More information

Original. M. Pang-Ngam 1, N. Soponpongpipat 1. Keywords: Optimum pipe diameter, Total cost, Engineering economic

Original. M. Pang-Ngam 1, N. Soponpongpipat 1. Keywords: Optimum pipe diameter, Total cost, Engineering economic Original On the Optimum Pipe Diameter of Water Pumping System by Using Engineering Economic Approach in Case of Being the Installer for Consuming Water M. Pang-Ngam 1, N. Soponpongpipat 1 Abstract The

More information

Speed Limit on Railway Curves. (Use of SuperElevation on Railways)

Speed Limit on Railway Curves. (Use of SuperElevation on Railways) Speed Limit on Railway Curves (Use of SuperElevation on Railways) Introduction When a train rounds a curve, it has a tendency to want to travel in a straight direction and the track must resist this movement,

More information

Available online at ScienceDirect. Procedia Engineering 84 (2014 )

Available online at  ScienceDirect. Procedia Engineering 84 (2014 ) Available online at www.sciencedirect.com ScienceDirect Procedia Engineering 84 (2014 ) 648 661 2014ISSST, 2014 International Symposium on Safety Science and Technology Modeling speed differential parameters

More information

Speed selection at sites with restrictive alignment: the US-191 case study

Speed selection at sites with restrictive alignment: the US-191 case study ISBN 978-88-548-5858-9 ISSN 1824-5463-13001 DOI 10.4399/9788854858596 pag. 71-82 selection at sites with restrictive alignment: the US-191 case study A. Al-Kaisy 1 T. Kreider 2 R. Pothering 2 1 Department

More information

20th. SOLUTIONS for FLUID MOVEMENT, MEASUREMENT & CONTAINMENT. Do You Need a Booster Pump? Is Repeatability or Accuracy More Important?

20th. SOLUTIONS for FLUID MOVEMENT, MEASUREMENT & CONTAINMENT. Do You Need a Booster Pump? Is Repeatability or Accuracy More Important? Do You Need a Booster Pump? Secrets to Flowmeter Selection Success Is Repeatability or Accuracy More Important? 20th 1995-2015 SOLUTIONS for FLUID MOVEMENT, MEASUREMENT & CONTAINMENT Special Section Inside!

More information

Analysis of Superelevation and Side Friction Factor on Horizontal Curve

Analysis of Superelevation and Side Friction Factor on Horizontal Curve Analysis of Superelevation and Side Friction Factor on Horizontal Curve Alkeshkumar Rabari 1, Prof. (Dr.) P. J. Gundaliya 2, Prof. Dipika Gupta 3 1Final year M.E. Student, Civil Engineering Department,

More information

2. LITERATURE REVIEW. Keywords: Design hourly factor ( K-factor), annual average daily traffic(aadt), design hour volume(dhv), road design

2. LITERATURE REVIEW. Keywords: Design hourly factor ( K-factor), annual average daily traffic(aadt), design hour volume(dhv), road design Study on Estimating Design Hourly Factor Using Design Inflection Point Won Bum Cho Senior Researcher, Korea Institute of Civil Engineering and Building Technology, Korea Ph.D. Student, Department of Transportation

More information

Development of Rattle Noise Analysis Technology for Column Type Electric Power Steering Systems

Development of Rattle Noise Analysis Technology for Column Type Electric Power Steering Systems TECHNICAL REPORT Development of Rattle Noise Analysis Technology for Column Type Electric Power Steering Systems S. NISHIMURA S. ABE The backlash adjustment mechanism for reduction gears adopted in electric

More information

Analysis and evaluation of a tyre model through test data obtained using the IMMa tyre test bench

Analysis and evaluation of a tyre model through test data obtained using the IMMa tyre test bench Vehicle System Dynamics Vol. 43, Supplement, 2005, 241 252 Analysis and evaluation of a tyre model through test data obtained using the IMMa tyre test bench A. ORTIZ*, J.A. CABRERA, J. CASTILLO and A.

More information