FOR HISTORICAL REFERENCE ONLY

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1 To: From: Subject: Electronic Distribution Recipients MINNESOT DEPRTMENT OF TRNSPORTTION Engineering Services Division Technical Memorandum No T-02 November 8, 2011 ernard J. rseneau, P.E., PTOE Deputy Commissioner / Chief Engineer Rumble Strips and StripEs on Rural Trunk Highways Expiration This Technical Memorandum supersedes both No T-03 (Edgeline Rumble StripEs Guidance for Rural Trunk Highways) and No TS-02 (Rumble Strips on Shoulders of Rural Trunk Highways) and shall remain in effect until November 8, 2016 unless superseded prior to this date or incorporated into the MnDOT Standard Plans, the Road Design Manual, and/or Traffic Engineering Manual. Implementation This policy shall be in effect for all programmed rural highway projects where the paved surface is constructed, reconstructed, or overlaid with a scheduled letting date after pril 1, This does not include preventive maintenance projects such as chip seals and microsurfacing; however, preventive maintenance projects on surfaces that have existing rumble strips or stripes shall ensure that these are perpetuated in accordance with the standards within this Technical Memorandum, particularly with respect to depth. District personnel should make every effort to implement this policy for projects which have been let prior to pril 1, 2012 and on which rumble strip and rumble stripe construction have not yet begun. ny paving constructed by MnDOT forces is exempt from the requirements of this Technical Memorandum. This policy applies to all projects on Rural Trunk Highways where the posted speed limit is 55 mph or higher. For the purpose of this Technical Memorandum a Rural Trunk Highway is defined in the Definitions section. Districts may implement this policy on Urban Trunk Highways. While this policy provides for standards that will require an increased use of rumble strips and stripes, it also provides for more flexibility and discretion on the part of the District. Notably, the District has the discretion for the preferred lateral placement and width of the shoulder rumble strip in order to abate noise concerns, accommodate bicyclists, acknowledge pedestrian use, and manage pavement conditions. The guidelines contained in this Technical Memorandum apply to all Rural Trunk Highways. However, other road authorities are encouraged to evaluate their needs accordingly. Introduction Detailed crash analysis has shown that lane departure crashes, such as run off the road, sideswipe and head-on crashes, on rural two-lane two-way highways in Minnesota result in an over represented number of fatalities and serious injuries. oth traditional pavement markings and rumble strips are used to decrease the number of lane departure crashes. Following the lead of other states, MnDOT experimented with combining traditional pavement markings and rumble strips into a rumble stripe, where the pavement marking is installed on the rumble strip. MnDOT issued guidance for the use of edgeline rumble stripes as part of Technical Memorandum No T-03. The NCHRP Report 641 shows that the use of rumble strips both on the shoulder and beneath the centerline result in a significant reduction of targeted crashes. This report can be found at the following -MORE-

2 Technical Memorandum No T-02 Rumble Strips and StripEs on Rural Trunk Highways November 8, 2011 Page 2 URL: dditionally, numerous states in the region have enacted systematic policies to require rumble strips and rumble stripes on their trunkline roadways. Michigan, Missouri, and North Dakota have policies requiring centerline rumble stripes, plus edgeline rumble stripes or shoulder rumble strips, on most of their rural trunkline roadways with higher speed limits. Iowa has a current statewide policy requiring the implementation of 4-foot paved shoulders and shoulder rumble strips on roads with DTs greater than Wisconsin has no policy on rumble stripes, but has shoulder rumble strips extensively on its trunkline roadway network. This Technical Memorandum strengthens the provisions of both Technical Memoranda that are being combined. ll of the requirements of the Technical Memorandum No TS-02 (Rumble Strips on Shoulders of Rural Trunk Highways) are still in place. The difference is that the requirement now extends to all high-speed rural roads where the paved shoulder is 4 or greater, instead of 6 or greater in the previous Memo. lso, the intention of this Technical Memorandum is to emphasize the use of centerline rumble stripes, and also provide stronger language and guidance than currently exists in Technical Memorandum No T-03 (Edgeline Rumble StripEs Guidance for Rural Trunk Highways). Studies have shown that the ambient noise decibel level generated by a vehicle driving over a properly constructed rumble strip is comparable to that of a truck passing by on a standard, non-rumbled surface. The noise from rumble strips may be more noticeable as the public is more accustomed to truck traffic, the frequency of the sound is different, and rumble hits tend to be more of an impulse noise. Purpose To provide centerline rumble stripes and/or shoulder rumble strips on all Rural Trunk Highways to reduce lane departure crashes, to provide increased centerline visibility during rainy conditions, and to guide motorists during snowy conditions when striping visibility is poor. Guidelines Definitions Shoulder Rumble Strips These are defined as rumble strips outside of the edgeline. Rumble StripEs Rumble stripes are defined as a rumble strip that contains a pavement marking stripe. These will be referred to as either edgeline rumble stripes or centerline rumble stripes. Rural Trunk Highway This is defined as a roadway segment that has minimal residential or commercial development, with little or no further development anticipated in the future. Officially, rural segments will be defined by language in Chapter 2 of the MnDOT ccess Management Manual. (Refer to the attached Reference 1, which shows the rural definition on page 10 in Chapter 2 of the MnDOT ccess Management Manual.) Requirements Shoulder Rumble Strips Shoulder rumble strips shall be placed on all rural highway projects where shoulders are constructed, reconstructed, or overlaid and where the posted speed limit is 55 mph or greater, and the paved shoulder width is 4 feet or greater. (This is a change from the previous standard, where shoulder rumble strips were required on highway paved shoulders of at least 6 feet in width.) Shoulder rumble strips may also be placed on rural trunk highways on shoulders less than 4 feet in width. The location of the shoulder rumble strip will depend upon the width of the shoulder see Figure 1 (Two-Way ituminous Roadway with Paved Shoulder Section View), Figure 2 -MORE-

3 Technical Memorandum No T-02 Rumble Strips and StripEs on Rural Trunk Highways November 8, 2011 Page 3 (Two-Way Concrete Roadway with Paved Shoulder Section View) and Figure 3 (Shoulder Rumble Strip on Divided Roadways) for typical dimensions. The District has the discretion for the lateral placement of the shoulder rumble strip in order to abate noise concerns and to accommodate bicyclists. Shoulder rumble strips shall also be placed on the left shoulder of multi-lane divided roads. Centerline Rumble StripEs Centerline rumble stripes shall be placed on all rural highway construction and maintenance projects where bituminous pavement is constructed, reconstructed, or overlaid and where the posted speed limit is 55 mph or greater. This applies to both multi-lane undivided and two-lane undivided highways. Centerline rumble stripes will not be required until pril 1, 2014 for concrete pavements that are constructed, reconstructed, or overlaid. This will allow the Department time to test out various installation methods on concrete pavement. Exceptions On rural highways where the paved shoulder width is 2 feet or less, shoulder rumble strips or edgeline rumble stripes may be placed on both sides of the road in lieu of a centerline rumble stripe. In all cases, edgeline rumble stripes may be substituted for shoulder rumble strips and still meet the standards within this Technical Memorandum. Shoulder rumble strips are not required in areas where there is a bus shoulder. However, it is assumed that bus shoulders will usually be installed in areas that are NOT defined as rural trunk highways in the ccess Management Guide. Shoulder rumble strips are not required in locations with guardrail or cable barrier implemented. Even in cases where shoulder rumble strips are not required due to a narrow paved shoulder width, their installation or the installation of an edgeline rumble stripe is encouraged for proactive safety reasons. Districts shall consider placing centerline rumble stripes and shoulder rumble strips on in-place shoulders at locations on which no construction, reconstruction, or overlay projects are scheduled in the near future as a systematic proactive safety measure. The District Materials Engineer should make recommendations regarding the structural adequacy of the in-place roadway and/or shoulder to receive rumble strips. Width of rumble strips Rumble strips are usually 12 in width. The width of the rumble strip can be reduced to within the range of 8-12 when paved roadway width is limited. 16 rumble is required on freeway segments. ny design of rumble strips that are smaller than 8 in width or that deviate from the 12 corrugation cycle detailed in Figures 4 through 8 shall require approval by the State Traffic Engineer. The standard width of rumble strips for centerline rumble stripes is 16. ny reduction from this shall require approval by the State Traffic Engineer. ll rumble strips shall meet any and all specifications for Milled Rumble Strips in the MnDOT Standard Specifications for Construction or Special Provisions. This includes a requirement that rumble strips be milled in bituminous pavement, and not rolled. -MORE-

4 Technical Memorandum No T-02 Rumble Strips and StripEs on Rural Trunk Highways November 8, 2011 Page 4 The placement of shoulder rumble strips and edgeline rumble stripes with respect to the traveled lane (shown in Figures 1 through 5, 7, and 8) may be deviated from at the discretion of the District. Such variation will be considered as informal design exception(s) and must be documented per Road Design Manual section Modifications for concrete pavement On concrete paved roadway surfaces, there are two options for how to install shoulder rumble strips. They include: Installing 3 long structural rumble strips on alternating panels, and also shoulder rumble strips on the adjacent paved bituminous shoulder. (Refer to Figures 2, 3C, and 7) Milling in either continuous or intermittent shoulder rumble strips outside the edgeline, but on the concrete surface. (Refer to Figures 3D and 8.) Centerline rumble stripes will not be required on concrete pavements until pril 1, 2014 in order test out various installation methods; but if they are to be installed, the current recommended installation is two 8 wide rumbles on either side of the centerline joint (each 2 away from the joint). Shoulder rumble strips on Figure 8 and the rumble strips beneath the centerline marking in Figures 7 and 8 may be hand formed in construction, so long as the final dimensions conform to the depth and pattern in the typical drawing of Section - in Figure 8, and the appropriate respective width called out in this Technical Memorandum. icycle travel on shoulders Shoulder widths that provide less than 4 feet of clear space with rumble strips are not considered adequate to accommodate bicyclists. Where practical and feasible, Districts are encouraged to provide a minimum of a 6 foot paved shoulder where shoulder rumble strips will be placed on trunk highways with existing or potentially significant bicycle travel. In order to meet the needs of bicyclists, flexibility has been built in to this Tech Memo. s stated above and reflected in the attachments, rumble strips as narrow as 8 as well as edgeline rumble stripes may be used at the discretion of the District. lso, while the dimensions in Figures 1 through 4 indicate the typical lateral placement of the shoulder rumble strip, the District has the discretion to deviate from this configuration with input from the State icycle Coordinator. Quality control of the lateral placement of rumble strips on these sections must be ensured. The longitudinal rumble strip pattern for shoulder rumble strips and edgeline rumble stripes on non-freeway segments is to include a 12 gap in each 60 cycle. Refer to Figures 4 and 5. This remains a standard from the previous two Technical Memoranda that are being combined. Districts may increase the gap from 12 in downhill sections with the approval of the State Traffic Engineer. Questions For information on the technical contents of this memorandum, please contact the State Work Zone and Pavement Marking Engineer at (651) ny questions regarding publication of this Technical Memorandum should be referred to the Design Standards Unit, DesignStandards.DOT@state.mn.us. link to all active and historical Technical Memoranda can be found at To add, remove, or change your name on the Technical Memoranda mailing list, please visit the web page ttachments: Reference 1 Figures END-

5 REFERENCE 1: Rural Definition from the MnDOT ccess Management Manual Mn/DOT ccess Management Manual Subcategory Rural This subcategory is intended for trunk highway segments that extend through agricultural, open, or forested areas with limited development. It is also assigned to areas planned for long-term, low-density development, characterized by scattered, large-lot residential development and limited commercial or industrial use. Highway segments outside municipalities are generally designated as Rural (Subcategory ), unless the area is undergoing or planned for urban-scale development. Highways in this subcategory are generally expected to operate at speeds of 50 mph or more; however, in areas lacking a complete supporting local road network, these highways will also be required to provide direct access to adjacent property. Special attention should be given to transition areas on the fringe of growing municipalities where local zoning may permit urban-type development without corresponding requirements for streets and utilities. Since the private access allowance in Rural (Subcategory ) areas is more permissive than in Urbanizing (Subcategory ) areas, it is important to appropriately categorize these transition areas in order to maintain long-term safety and mobility goals for the corridor. In some geographically-large municipalities, full urbanization may not be anticipated within the next 20 (or more) years. Highway segments extending through areas of municipalities planned to remain rural in character are designated Rural (Subcategory ). Figure 2.3 illustrates a municipal area with both a Rural (Subcategory ) segment that extends into an area that is not planned for development and an Urbanizing (Subcategory ) segment that extends into a transition area outside the city s boundary. Figure 2.3: Category ssignments in a City Rural Urbanizing Urban Core City oundary

6 FIGURE 1 - TWO-WY ITUMINOUS RODWY WITH PVED SHOULDER - SECTION VIEW FIGURE 1 (ITUMINOUS PVEMENT OPTION 1 - SHOULDER RUMLE STRIPS) 4 0" OR GRETER 4 0 OR GRETER 8"-1 RUMLE GP FIGURE 1C CENTERLINE S CENTERLINE S 4 0" OR GRETER 4 0 OR GRETER LESS THN 4 0" LESS THN 4 0" 8" RUMLE STRIP 8"-1 RUMLE (3) 16 RUMLE (CONTINUOUS) (1) VR. (2) VR. (2) FIGURE 1 (ITUMINOUS PVEMENT OPTION 2 - EDGELINE RUMLE S) 16 RUMLE (CONTINUOUS) (1) GP CENTERLINE S (ITUMINOUS PVEMENT WITH LESS THN 4 PVED SHOULDERS) 16 RUMLE (CONTINUOUS) (1) 8" RUMLE STRIP GP TYP. TYP. ( MIN.) ( MIN.) (1) CENTERLINE RUMLE REQUIRED ON TWO-WY ITUMINOUS RODWYS ONLY. SEE FIG. 6 FOR DETILS. (2) WHERE SHOULDER WIDTH IS LESS THN 6 ; 1 WHERE SHOULDER WIDTH IS 6 OR GRETER. (3) INTERMITTENT PTTERN. USE 8" RUMLE STRIP/ WHERE SHOULDER WIDTH IS LESS THN 6. 8"-1 RUMLE (3) 8"-1 RUMLE

7 FIGURE 2 - TWO-WY CONCRETE RODWY WITH PVED SHOULDER - SECTION VIEW FIGURE 2 (CONCRETE PVEMENT OPTION 1 - STRUCTURL EDGELINE ND SHOULDER RUMLE STRIPS) C L 4 0" OR GRETER 4 0 OR GRETER 8"-1 RUMLE STRIP (2) LESS THN 4 0" RUMLE RUMLE CONCRETE PVEMENT WIDTH FIGURE 2 FIGURE 2C CONCRETE PVEMENT WIDTH CENTERLINE S CENTERLINE S RUMLE (CONCRETE PVEMENT OPTION 2 - EDGELINE RUMLE S) CONCRETE PVEMENT WIDTH 8 CENTERLINE S RUMLE 8"-1 RUMLE STRIP (2) 4 0" OR GRETER 4 0 OR GRETER 1 RUMLE RUMLE (OPTIONL) (1) 8 RUMLE (OPTIONL) (1) 1 RUMLE (CONCRETE PVEMENT WITH LESS THN 4 PVED SHOULDERS) C L C L 8 8 RUMLE (OPTIONL) (1) 8 8 LESS THN 4 0" (1) CENTERLINE RUMLE OPTIONL. SEE FIGS. 7 ND 8 FOR DETILS. (2) USE 8" INTERMITTENT WHERE SHOULDER WIDTH IS EQUL TO OR GRETER THN 6 ND LESS THN 8. USE 1 INTERMITTENT WHERE SHOULDER WIDTH IS 8 OR GRETER. NOT NECESSRY WHERE SHOULDER WIDTH IS LESS THN 6. (3) WHERE SHOULDER WIDTH IS LESS THN 6 USE GROUND-IN INTERMITTENT OPTION. STRUCTURL RUMLES MY E USED IN LL OTHER CSES. SEE FIG. 7 ND 8 FOR RUMLE STRIP OPTIONS, PLCEMENT, ND DIMENSIONS.

8 FIGURE 3 - SHOULDER RUMLE STRIP ON DIVIDED RODWYS - SECTION VIEW FIGURE 3 ITUMINOUS FREEWY (ONE RODWY SHOWN) MEDIN SHOULDER OUTSIDE SHOULDER 16"RUMLE STRIP (CONTINUOUS) MEDIN SHOULDER 16"RUMLE STRIP (CONTINUOUS) MEDIN SHOULDER MEDIN SHOULDER 16" RUMLE 1 RUMLE STRIP FIGURE 3 ITUMINOUS MULTI-LNE (ONE RODWY SHOWN) FIGURE 3C CONCRETE PVEMENT WIDTH FIGURE 3D CONCRETE FREEWY/MULTI-LNE OPTION (ONE RODWY SHOWN) CONCRETE PVEMENT WIDTH CONCRETE FREEWY/MULTI-LNE OPTION (ONE RODWY SHOWN) 8" RUMLE 2 RUMLE 1 RUMLE 16"RUMLE STRIP 2 (CONTINUOUS) OUTSIDE SHOULDER VR. (1) 16"RUMLE STRIP OUTSIDE SHOULDER 16" RUMLE STRIP (2) OUTSIDE SHOULDER (1) WHERE SHOULDER WIDTH IS LESS THN 6 ; 1 WHERE SHOULDER WIDTH IS 6 OR GRETER. (2) USE 8" INTERMITTENT WHERE SHOULDER WIDTH IS EQUL TO OR GRETER THN 6 ND LESS THN 8. USE 1 INTERMITTENT WHERE SHOULDER WIDTH IS 8 OR GRETER. USE 16" CONTINUOUS ON FREEWY. NOT NECESSRY WHERE SHOULDER WIDTH IS LESS THN 6. (3) SEE FIG. 7 ND 8 FOR RUMLE STRIP OPTIONS, PLCEMENT, ND DIMENSIONS.

9 FIGURE 4 - ITUMINOUS SHOULDER RUMLE STRIP FIGURE 4 - PLN VIEW 8-16 VR. (1) 8"- 16 VR. (1) WIDTH 7" ( + - CONTINUOUS 1/) INTERMITTENT PTTERN WIDTH 7" (+ - 1/) EDGE OF MINIMUM DEPTH 3/8 MXIMUM DEPTH 1/ 8" - 16 (1) FINISHED SHOULDER 48 RUMLE STRIP 12 GP FIGURE 4 - PLN VIEW 5 WIDTH 7" ( + - 1/) EDGE OF MIN. DEPTH 3/8 MX. DEPTH 1/ 5" UNIFORMLY 1 SHOULDER WIDTH SECTION - SECTION - (1) REFER TO FIGURES 1 ND 3 FOR SPECIFIC PPLICTIONS.

10 FIGURE 5 - ITUMINOUS EDGELINE RUMLE FIGURE 5 - PLN VIEW CONTINUOUS PTTERN 8"- 1 8"- 1 WIDTH 7" ( + - 1/) PINT WIDTH 7" (+ - 1/) PINT MINIMUM DEPTH 3/8 8" - 1 (1) 48 RUMLE FINISHED SHOULDER MXIMUM DEPTH 1/ EDGE OF FIGURE 5 - PLN VIEW INTERMITTENT PTTERN 5 WIDTH 7" ( + - 1/) 12 GP MIN. DEPTH 3/8 MX. DEPTH 1/ 5" UNIFORMLY 1 SHOULDER SHOULDER SECTION - SECTION - (1) USE 8" RUMLE WHERE SHOULDER WIDTH IS LESS THN 6.

11 FIGURE 6 - ITUMINOUS CENTERLINE RUMLE - PLN VIEW WIDTH 7" (+ - 1/) SECTION - MINIMUM DEPTH 3/8 MXIMUM DEPTH 1/ C L WIDTH 7" ( + - 1/) MIN. DEPTH 3/8 MX. DEPTH 1/ 1 SECTION -

12 FIGURE 7 - CONCRETE PVEMENT OPTION - STRUCTURL RUMLE STRIP CONCRETE PVEMENT WIDTH PVED SHOULDER WIDTH WIDTH MINIMUM DEPTH 3/8 MXIMUM DEPTH 1/ 15 0" PNEL (TYP.) 3 0" RUMLE STRIP SECTION C-C EDGE OF CONCRETE PVEMENT PLN VIEW 36" EDGE OF FINISHED SHOULDER 18 (TYPICL) (1) CENTERLINE RUMLE (OPTIONL) (2) EDGE OF PVED SHOULDER 1" RDIUS 1"DEPTH EDGE OF CONCRETE PVEMENT D C C MIN. DEPTH 3/8 MX. DEPTH 1/ 1 WIDTH 7" 8" 8" ( + - 1/) C L (3) D 6" SECTION D-D SECTION - SECTION - (1) FOR DIVIDED RODWYS USE 1 0" ON INSIDE LNE ND 2 0" ON OUTSIDE LNE. (2) OMIT ONE CORRUGTION SO THT THERE IS T LEST 6" CLERNCE ON EITHER SIDE OF TRNSVERSE JOINT. (3) INTERMITTENT DESIGN SHOWN FOR ILLUSTRTION PURPOSES. REFER TO FIGURE 4 FOR INTERMITTENT PTTERN.

13 FIGURE 8 - CONCRETE PVEMENT OPTION - CONCRETE RUMLE STRIP CONCRETE PVEMENT WIDTH WIDTH 8" MINIMUM DEPTH 3/8 MXIMUM DEPTH 1/ (2) 15 0" PNEL (TYP.) CENTERLINE RUMLE (OPTIONL) (2) 8" - 1 (1) SECTION - C L SECTION C-C EDGE OF CONCRETE PVEMENT FINISHED SHOULDER PLN VIEW WIDTH 7" ( + - 1/) MINIMUM DEPTH 3/8 MXIMUM DEPTH 1/ EDGE OF CONCRETE PVEMENT (3) 8" (2) C C MIN. DEPTH 3/8 MX. DEPTH 1/ 1 SECTION - (1) REFER TO FIGURES 2 ND 3 FOR SPECIFIC PPLICTIONS. (2) OMIT ONE CORRUGTION SO THT THERE IS T LEST 6" CLERNCE ON EITHER SIDE OF TRNSVERSE JOINT. (3) CONTINUOUS DESIGN SHOWN FOR ILLUSTRTION PURPOSES. REFER TO FIGURE 4 FOR INTERMITTENT PTTERN.

14 FIGURE 9 - SHOULDER RUMLE STRIP - PPROPRITE REKS 50 FT. FIGURE 9 LEFT TURN LNE RUMLE STRIPS RUMLE STRIPS RUMLE STRIPS FIGURE 9 RIGHT TURN LNE 50 FT. RUMLE STRIPS RUMLE STRIPS RUMLE STRIPS FIGURE 9C ENTRNCE RODS 130 FT. RESIDENTIL/ COMMERCIL ENTRNCE OR FRONTGE ROD FIELD ENTRNCE FIGURE 9D CCELERTION LNE FIGURE 9E DECELERTION LNE

15 FIGURE 10 - CENTERLINE RUMLE - PPROPRITE REKS (1) TOWNSHIP ND COUNTY RODS, COMMERCIL ENTRNCES, ND RESIDENTIL ENTRNCES WITH 200 REK ENGINEER S DISCRETION STRIP CENTERLINE RUMLE S 200 REK STRIP CENTERLINE FIELD ENTRNCES RUMLE S (1) PVEMENT S ND STRIPING SHLL E COMPLINT WITH THE CURRENT TRFFIC ENGINEERING MNUL ( TEM ) ND THE CURRENT MINNESOT MNUL OF UNIFORM TRFFIC CONTROL DEVICES ( MN/MUTCD )