TRANSPORT and ROAD RESEARCH LABORATORY. Department of the Environment Department of Transport SUPPLEMENTARY REPORT 566

Transcription

1 TRANSPORT and ROAD RESEARCH LABORATORY Department of the Environment Department of Transport SUPPLEMENTARY REPORT 566 EFFECTS OF A LORRY CONTROL AT LYMM, CHESHIRE by A W Christie and J Prudhoe Any views expressed in this Report are not necessarily those of the Department of the Environment or of the Department of Transport Freight Division Transport Systems Department Transport and Road Research Laboratory Crowthorne, Berkshire 1980 ISSN

2 Ownership of the Transport Research Laboratory was transferred from the Department of Transport to a subsidiary of the Transport Research Foundation on 1 st April This report has been reproduced by permission of the Controller of HMSO. Extracts from the text may be reproduced, except for commercial purposes, provided the source is acknowledged.

3 CONTENTS Page Abstract 1. Introduction 1.1 The control 1.2 Surveys 2. Effect on traffic flows 2.1 Traffic on routes through Lymm Flows of HGVs Observance of the control 2.2 Traffic on routes through Sale and Urmston 2.3 Traffic on other routes 3. Effect on operators' costs 4. Effects on congestion, nuisance and accidents 4.1 Congestion 4.2 Nuisance 4.3 Accidents 5. Discussion 6. Conclusions 7. Acknowledgements 8. References (C) CROWN COPYRIGHT 1980 Extracts from the text may be reproduced, except for commercial purposes, provided the source is acknowledged

4 EFFECTS OF A LORRY CONTROL AT LYMM, CHESHIRE ABSTRACT TRRL has monitored a lorry control at Lymm, Cheshire which has diverted some 220 heavy lorries per day, many carrying dangerous loads, away from the narrow, tortuous and hilly roads through the village. Although the main aim of the control is to reduce the possibility of major accidents involving large vehicles carrying hazardous loads through Lymm it has not proved possible to evaluate its effect on the probability of such accidents occurring there or elsewhere. The diverted vehicles now use better, but longer, routes at an extra cost to operators averaging about 1.50 per one-way trip and totalling nearly 100,000 annually. They now pass more dwellings than formerly but, in general, the individual HGV flow increases are less than the individual flow decreases and are on roads which already carried much greater total traffic flows. 1. INTRODUCTION As part of a programme to monitor the effects of plans to influence the routes used by heavy goods vehicles, the Transport and Road Research Laboratory has studied an experimental weight restriction which came into operation in September 1978 at Lymm, Cheshire, a village forming part of the Borough of Warrington and lying close to its boundary with the Borough of Trafford, Greater Manchester (see Figure 1). The control was introduced primarily on grounds of safety, unlike the control in the Windsor area of Berkshire studied previously 1 which was based mainly on amenity considerations. At Lymm the main aim was to relieve the low standard roads through the area from the large vehicles carrying hazardous loads (such as petrol, chemicals and liquified gases) generated by the nearby industrial complexes of Carrington and Partington which were considered to create a potential accident hazard to pedestrians, property and other vehicular traffic. With the collaboration of all the local authorities concerned changes in lorry traffic were surveyed and, from the results obtained, the Laboratory has evaluated the environmental changes, changes in congestion costs and changes in operators' costs resulting from the control. It has not, however, been possible to assess how the total dangers from hazardous loads or the distribution of such dangers have changed. 1.1 The control The lorry control applies to through routes in a zone covering the part of Lymm to the north of the principal road, A56. The main route controlled is the A6144 which runs in a north-easterly direction from the A56, through the village centre towards Partington, Carrington and Sale (see Figure 1). The control applies also to a number of less important alternative routes through and around the village, including the B5159 (see Figure 2). The control prohibits heavy goods vehicles of over 3 tons unladen weight (referred to subsequently in the report as HGVs) from entering the village except those requiring access to Lymm or used for 'agricultural purposes'. The A6144 through Lymm is narrow (down to 5m in places), tortuous and hilly. The road descends from the south-west at a gradient of 10 per cent culminating in a right-angled bend into the main shopping street (see Plate 1). This street contains further bends and a steep rise to a bridge over the Bridgewater Canal. This is

5 particularly hazardous since the approaches to the bridge are very steep and that from the north is at right angles (see Hate 2). Articulated vehicles have sometimes grounded on the bridge apex. The rescue services maintain that should there be a major accident involving a dangerous load in the centre of Lymm it would be very difficult for them to get to it quickly. The north-eastern end of the protected length of the A6144 is semi-rural in character and contains a railway level-crossing with a manually-operated barrier. The other routes prohibited in the Lymm area are of an even lower standard - the roads are narrower and have restricted headroom (about 9 ft) where they pass under bridges carrying the Bridgewater Canal. On the B5159 there are right-angled approaches on both sides of the bridge. There are several combinations of the motorways M6, M56, M62 and M63, and the principal roads A56 and A57 which can be used as an alternative to the A6144 by HGVs travelling between Warrington or the M6/M56 junction and the western parts of Manchester. There is, however, no high-quality access road from these roads into the Carrington area. The main remaining possibilities for HGVs are (i) from the A56 at Sale via A6144, Carrington Lane (see Hate 3) (ii) from junctions 3, 4 and 5 of M63 at Urmston via B5158, Flixton Road (see Hate 4). Though these routes do not have all the disadvantages of the A6144 through Lymm, neither is ideal: for example there is a difficult right-angled bend where the B5158 crosses the river Mersey. Both pass through residential areas and the latter through two local shopping centres. 1.2 Surveys Some of the surveys for the study formed part of the normal lorry planning process of the local authorities whilst others, necessary for the fuller analysis proposed by TRRL, were carried out either by the local authorities at the request of the Laboratory or by the Laboratory itself. The HGV surveys used to provide the data for the analyses are listed below:- Location Date Organising authority Type of survey Near SPI* on A6144 Tuesday, 21 December 1976 Trafford BC 'Before' 0 and D survey t SP1 on A6144 Friday, 16 June 1978 Cheshire CC 'Before' 0 and D survey SP1 on A6144 Thursday, 26 October 1978 TRRL 'After' HGV count A6144 and B5159 through Lymm Monday, 13 November 1978 to Wednesday, 15 November 1978 TRRL Survey of compliance SP1 on A6144 SP2* on A6144 Friday, 16 March 1979 Friday, 16 June 1978 Cheshire CC Trafford BC 'After' O and D survey "Before' HGV count SP2 on A6144 Monday, 23 April to Wednesday, 25 April 1979 TRRL 'After' HGV count A6144 east of SP2 Friday, 8 September 1978 Trafford BC 'Before' O and D survey A6144 east of SP2 Friday, 23 February 1979 Trafford BC 'After' O and D survey B5158, A57 and M62 Thursday, 5 July 1979 TRRL Registration number matching * SP1 and SP2 are survey points shown in Figure 1. t "O and D' is an abbreviation for 'origin and destination'. 2

6 2. EFFECT ON TRAFFIC FLOWS 2.1 Traffic on routes through Lymm Flows of HGVs: Table 1 gives estimates of the weekday flows of HGVs in Lymm before and after the introduction of the control. The figures are two-way flows for the 12-hour period hours. The 'before' figures were obtained in an O and D (origin and destination) survey carried out by Cheshire County Council in June 1978 at survey point SP1 on the A6144 on the northern side of the junction with the B5159 (Figure 1). The figures therefore include any 'through' vehicles using the B5159 which, though subject to the control, avoid the village centre. The 'after' figures come from a classified count of goods vehicles carried out by TRRL at SP1 in October TABLE 1 Counts of HGVs in Lymm 12-hour flows (1) 2 axles 3 or more axles(2) All HGVs Before introduction of control(3) (134) 308 After introduction of control(4) (5) 109 Change (- 129) Percentage change (-96) -65 Notes: (1) Two-way flows, hours. (2) Figures in brackets are numbers of HGVs with 4 or more axles included in the unbracketted figures. (3) Cheshire County Council O and D survey of Friday 16 June (4) TRRL classified count of Thursday 26 October The figures in Table 1 indicate a reduction of 199 HGVs per 12-hour weekday (65 per cent) including 161 HGVs with three or more axles (91 per cent). The reductions in numbers of two-axle and multi-axle HGVs are both highly significant (one per cent confidence level). The data in Table 1 are from one-day counts. The 'after' figures agree well with those obtained in a shorter O and D survey by Cheshire CC at the same site on Friday, 16 March 1979 whilst the 'before' figures are close to those obtained in an O and D survey by Trafford BC on Tuesday, 21 December 1976 on an adjacent section of the A Observance of the control: In Table 2 the HGVs referred to in Table 1 are divided into three categories according to the type of trip being made: (1) trips with a stop in the control area, (2) through trips by HGVs exempt for agricultural purposes and (3) through trips made by non-exempt HGVs. Those in the last category after the introduction of the control are violating it and the percentage which they represent of the vehicles on such trips before the introduction of the control is termed the 'violation rate'.

7 TABLE 2 Through arid stopping journeys by HGVs in Lymm 12-hour flows (1) 2 axles 3 or more axles All HGVs Before introduction of control After introduction of control Change Stopping journeys 46 Through journeys by exempt types of HGV 9 Through journeys by non-exempt types of HGV 76 All journeys by HGVs 131 Stopping journeys 53 Through journeys by exempt types of HGV Through journeys by non-exempt types of HGV 34 All journeys by HGVs 93 Stopping journeys +7 Through journeys by exempt types of HGV -3 Through journeys by non-exempt types of HGV -42 All journeys by HGVs -38 Violation rate (per cent)(2) Notes: (1) (2) Sub-division of flows in Table 1, see text Section Through journeys by non-exempt HGVs (with control) Violation rate = Through journeys by non-exempt HGVs (before control) x 100 Trips were categorised according to the answers given by drivers interviewed in the Cheshire County Council O and D surveys, though in the case of the 'after' survey the numbers had to be grossed up according to the results of the TRRL classified count to cover the full 12-hour period. Since it could not be assumed that, in the 'after' O and D survey, drivers violating the control would answer truthfully, independent checks were made by TRRL. To identify through vehicles two methods were used in differentsituations: one was to follow the vehicles whilst the other was to record vehicle registration numbers at the entrances and exits of the control area together with the entry and exit times. The results of these checks were in good agreement with answers given in the O and D survey which have therefore been accepted as the basis for Table 2. It will be seen that the violation rate for two-axle HGVs was about 45 per cent whilst that for multi-axle vehicles was only about 6 per cent. This difference is statistically significant at the 0.1 per cent confidence level. The TRRL checks indicated that about 43 per cent of the two-axle HGVs violating the control chose to use the B5159 (which has only a 9ft headroom where it passes under the Bridgewater Canal) instead of following the A6144 through the centre of Lymm where, presumably, the probability of detection was greater. 4

8 2.2 Traffic on routes through Sale and Urmston The results of the O and D surveys carried out by Cheshire CC before the introduction of the control showed that almost all the HGVs passing through Lymm without stopping were bound for, or originated from, the industrial complexes of Carrington and Partington or, in a few cases, places lying between these and Lymm. Therefore, after the introduction of the control, most of the diverted vehicles would have had to use other routes into the Carrington area, the main possibilities being: (i) and (ii) A6144 Carrington Lane from Sale B5158 Flixton Road from Urmston. Some HGVs would also cease to use these roads (those on non-exempt non-stop journeys through the entire area including both Lymm and Carrington). However they were so few as to have little effect on the flow changes on these roads. As the overall environmental and economic assessments of the control are dependent on which of these routes was chosen by the majority of diverted vehicles, 'before' and 'after' traffic counts were made on both these roads near the point where they join (survey point SP2 in Figure 1). However, here flows of HGVs are much higher than in Lymm with the result that the changes to be detected are only of the order of 10 per cent of the initial HGV flows and could easily be masked by the day-to-day, seasonal and long-term variations to be expected in freight flows. Not surprisingly, therefore, the changes indicated by 'before' and 'after' traffic counts were not in good agreement with the total change to be expected, or the split of the diverted traffic between the two roads as estimated by 'least-cost' re-routeing. The results of'before' and 'after' O and D surveys carried out by Trafford BC on Carrington Lane provided further estimates of flow changes on that road since every HGV was stopped for interview. Since evidence of this type was not available for Flixton Road (B5158) a registration number matching survey was undertaken to identify HGVs likely to have transferred to this road as a result of the control at Lymm. Using all the available evidence the best estimates of the HGV flow changes on Carrington Lane and Flixton Road arising from the Lymm control are as in Table 3. These are the flows which would arise if not all of the drivers of diverted vehicles chose the cheapest route but exercised a preference for Flixton Road even though it was up to 50p more expensive than the alternative route in terms of operating cost. The analysis is discussed in Working Paper: Freight 022*. TABLE 3 Estimated HGV flow changes on Carrington Lane and Flixton Road due to the control at Lymm 12-hour flow changes 2 axles 3 or more axles All HGVs Carrington Lane (A6144, Sale) Flixton Road (B5158, Urmston) Both roads * The Working Paper: Freight 022 may be obtained by written application to the Head of Freight Division, Transport and Road Research Laboratory. In the remainder of this report, the Working Paper will be referred to as reference 2.

9 2.3 Traffic on other routes Assuming that the estimated increases of HGV traffic on Carrington Lane and Flixton Road are correct, the complete pattern of flow changes on the road network in the Warrington/Manchester area is as shown in Figure 3. The major changes in the 12-hour weekday flows of HGVs, in addition to those already discussed, are an increase of 80 on the A56 through Altrincham, an increase of 70 on the A57 through Irlam and an increase of 110 on the M63 motorway crossing of the Manchester Ship Canal. 3. EFFECT ON OPERATORS' COSTS Changes in operators' costs due to the introduction of the control in Lymm were estimated assuming the pattern of flow changes shown in Figure 3 and using the operating costs shown in Table 4 which are representative of costs at September 1978: the method is outlined in reference 2. TABLE 4 Vehicle operating costs including overheads (September 1978) 2-axle goods vehicles over 3 tons UW 3-axle goods vehicles Goods vehicles with 4 or more axles Standing costs (p/min) Running costs (p/km) If there were complete compliance with the control the mean increases in journey distance, time and cost would be as in Table 5 which also shows the corresponding estimated total daily increases in the costs of operators. Table 6 lists the estimates of the daily, weekly and annual increases in the total operating costs of operators for both full compliance and the observed degrees of compliance shown in Table 2. TABLE 5 Distance, time and cost changes for diverted HGVs Mean distance increase per trip (km) 2 axles or more axles 8.8 All HGVs 8.1 Mean time increase per trip (min) Mean cost increase per trip ( ) Total daily cost increase* ( ) * 12-hour working day ( hours), assuming full compliance 6

10 TABLE 6 Total increases in vehicle operators' costs Full compliance (~) Observed compliance(l) ( ) 12-hour weekday hour weekday(2) Average week(3) 2,200 1,900 Year (52 weeks) 113,000 98,000 Notes: (1) Violation rates: 45 per cent for two-axle HGVs and 6 per cent for multiaxle HGVs. (2) 12-hour values plus 10 per cent. (3) 5½ times the weekday values. 4. EFFECTS ON CONGESTION, NUISANCE AND ACCIDENTS 4.1 Congestion Any changes in goods vehicle traffic must have some effect on the speeds of other vehicles and, therefore, on the travel and transport costs of their operators and occupants. An estimate of the changes in the 'congestion costs' resulting from the re-routeing of HGV traffic caused by the lorry control at Lymm has been made for the urban sections of the road network. Full classified traffic counts were obtained for as many as possible of the urban road links experiencing substantial changes in HGV traffic: most of these data were available from the local authorities but in a few cases counts had to be made by TRRL. Speeds were measured as described in reference 2. The estimates of the changes in speed likely to arise from the changes in the HGV component of flow were made using a result derived from an unpublished analysis of the data collected for the Urban Congestion Study of 19763'4. This indicated that it requires a flow change of 50 HGVs per hour per lane to produce a speed change of 1 km/h. Changes in travel cost were then derived from changes in travel time by applying standard Department of Transport values of time and vehicle operating costs. From this analysis it appears that there would be a reduction in congestion costs of about 4 per day in Lymm and Partington on the urban sections of the roads from which HGVs have been removed. In Irlam, Urmston and Sale there would be an increase in congestion costs of about 10 per day on the urban sections of the roads to which HGVs have diverted. The net change would be an increase of about 6. Any change in congestion costs on the rural sections of the roads concerned is likely to be even smaller and has not been estimated.

11 4.2 Nuisance The following measure of the change in people's exposure to lorry nuisance was used: (Number of dwellings fronting the road and within 100m of its centreline) x (Change in the daily number of HGVs) Whilst this measure is easy to calculate and its meaning is readily understandable, it gives only an approximate indication of nuisance changes since it does not take into account such important factors as: (i) (ii) (iii) total traffic flow, the distance of dwellings from the traffic and how many people live in them, changes in nuisance to pedestrians and occupants of other buildings (such as schools and hospitals). The numbers of dwellings on affected roads were read off Ordnance Survey maps of scale 1:2500. Shops are included with dwellings since they cannot be distinguished on the maps. Fiats shown separately are also included: most purpose-built flats will have been counted by this technique but not those consisting of sections of large houses. Changes in 24-hour weekday flows of HGVs (assumed to be 10 per cent greater than the measured 12-hour flows) were used in the calculations. Daily flow changes have been used since these are likely to be easier to appreciate than annual changes. The main environmental changes are summarised in Table 7; although there were undoubtedly changes on roads not included in the table they were on a smaller scale. In the case of motorways it has been assumed that additional lorries give rise to negligible nuisance. The values in the table refer to a 24-hour weekday and to the degree of compliance found in the surveys. For convenience the roads have been grouped by locality. There were substantial reductions in the exposure of dwellings to lorry nuisance on the protected routes through Lymm and Partington. In Carrington there was a very small reduction due to the removal of a few through vehicles. In Irlam, Urmston and Sale there were large increases in the nuisance index on the routes to which the affected vehicles diverted. Within Warrington there were some transfers of nuisance but their magnitudes are known only approximately since they depend on the precise locations of lorry destinations within the town and these are not known. In all some 1150 dwellings have experienced an average reduction of about 115 in the daily number of passing HGVs whilst about 5150 dwellings have experienced an average increase of about 65. In terms of the nuisance exposure index there has been an increase of 197,000 units. This index, however, makes no allowance for other traffic on the roads experiencing the changes: the total traffic volumes on the roads experiencing increased HGV flows are on average about three times as great as on the A6144 through Lymm and Partington where the major reductions in HGV flows were achieved.

12 TAB LE 7 Changes in exposure of dwellings to lorry nuisance (24-hour weekday) Locality Lymm Route A6144 from A56 to B5159 B5159 from A6144 to A56 B5158 from A56 to A50 A56 from A6144 to B5159 Number of dwellings Mean change in daily HGV flow Change in nuisance exposure* Locality total Partington A6144 from B5159 to Carrington Carrington A6144 from Partington to B Warrington A57 from M6 to A A50 from A57 to town centre A50 from town centre to A56 A56 from A50 to A Locality total Irlam A57 from M63 to M Urmston B5158/B5214 from A6144 to M Sale A6144 from B5158 to A A56 from A6144 to M A56 from A6144 to M Locality total Mere A556 from M56 to M Dwellings experiencing nuisance reductions Dwellings experiencing nuisance increases Net change * Number of dwellings x change in daily HGV flow - not necessarily exactly the product of the figures in the previous two columns since most figures have been rounded. 4.3 Accidents Although the control was introduced on safety grounds there had been few accidents involving HGVs in Lymm: on the A6144 there were only three recorded accidents to HGVs in the four years prior to the introduction of the control (one serious, one slight and one involving damage only). In the ten months following the introduction of the control there are no records of accidents, involving HGVs on the A6144 in Lymm but no firm conclusions regarding the effect of the control on such accidents can be drawn from these figures. 9

13 However Warrington BC's prime concern was with the possibility of a major catastrophe involving a hazardous load. Though there has not been such an accident before (or since) the introduction of the control, there was a possibility of one occurring and there is no way of ascertaining whether the control has prevented any in Lymm, or, indeed, resulted in any occurring elsewhere. All that can be said, at present, is that, although the diverted HGVs no longer face the special hazards of the restricted routes, they now travel further on busier (albeit better) roads and pass more dwellings (as indicated by the nuisance exposure index). 5. DISCUSSION Prior to the introduction of the control about 175 multi-axle HGVs used the low standard roads through Lymm during a 12-hour weekday, the great majority being on through trips to or from the industrial complexes of Carrington and Partington and many carrying dangerous goods. There were, in addition, about 130 two-axle HGVs. The control has reduced these numbers to about 15 and 90 respectively. The corresponding 24-hour volumes would be about ten per cent greater: this has been assumed in the analysis of the environmental and economic effects of the control. For multi-axle HGVs the violation rate is only about 5 per cent but for two-axle HGVs, which are able to use minor roads round the outskirts of Lymm, the violation rate is about 45 per cent. There are only two feasible alternative routes to Carrington: one through Urmston and one through Sale. Largely because the volumes of traffic on these roads are high relative to the changes caused by the control at Lymm difficulty was experienced in establishing the new pattern of rowof the diverted vehicles. From a consideration of evidence from several different surveys it appears most likely that about two-thirds of the vehicles to and from Carrington now use the route through Urmston and about one-third uses the route through Sale. Though neither of these routes is entirely suitable for HGV traffic they do not have all the unsuitable features of the roads through Lymm. The new routes of the diverted vehicles are of a higher standard than their former routes through Lymm but, in most cases, are longer and busier and pass more dwellings. Whilst about 1150 dwellings experience an average reduction of about 115 passing HGVs per day about 5150 experience an average increase of about 65 HGVs per day. If the product of the number of dwellings and the change in the daily HGV flow is used as the index of nuisance change, a net increase of 197,000 units is obtained. However, this index may exaggerate the adverse balance of effects because the increases in HGV flows were, in general, less than the reductions and the existing total traffic flows were, on average, about three times as high on the roads experiencing the increases as on roads experiencing the reductions. Less weight should probably therefore be ascribed to the increases than to the reductions. The diverted vehicles have to travel, on average, an extra 8 km taking an extra 6½ minutes to do so and increasing operators' costs by about 1.50 per one-way trip. In a full year the increase in operators' costs is about 100,000; with full compliance it would be about 115,

14 The effect of the changes on traffic congestion costs appears to be negligible. Although the main purpose of the control was to remove the possibility of a major accident involving a large vehicle carrying a hazardous load in Lymm, it has not proved possible to evaluate how it has affected the probability of such accidents occurring there or elsewhere. The case of Carrington and Partington illustrates how problems of access to industrial sites can still arise even in areas well provided with motorways. 6. CONCLUSIONS (1) The control has removed some 220 HGVs (including about 180 multi-axle HGVs) per weekday from low standard roads through Lymm. (2) Most of the diverted vehicles were travelling to or from the Carrington and Partington industrial complexes and now use roads of a higher but not ideal standard. (3) The diverted vehicles pass more dwellings than formerly but, on average, the increases in HGV flows are only half the decreases and are to better roads carrying three times as much total traffic. (4) The additional costs to operators average about 1.50 per one-way trip and total 100,000 annually. (5) Although the main purpose of the control is to remove the possibility of a major accident involving a hazardous load in Lymm, it has not proved possible to estimate its effect on the probability of such accidents occurring there or elsewhere. 7. ACKNOWLEDGEMENTS The work described in this report was carried out in the Freight Division (Division Head: Dr P J Corcoran) of the Transport Systems Department of TRRL. The authors gratefully acknowledge the co-operation of: Cheshire County Council, Greater Manchester Council, Warrington Borough Council, Trafford Borough Council and several of the major firms in the area. 8. REFERENCES 1. CHRISTIE, A W, R S HORNZEE and T ZAMMIT. The effects of lorry controls in the Windsor area. Department of the Environment Department of Transport, TRRL Report SR 458. Crowthorne, 1978 (Transport and Road Research Laboratory).. CHRISTIE, A W and J PRUDHOE. Effects of a lorry control at Lymm, Cheshire: supplementary information. TRRL Working Paper: Freight 022. (Unpublished but available on written request to the Head of Freight Division, Transport Systems Department, Transport and Road Research Laboratory, Crowthorne, Berkshire). 11

15 . MARLOW, M and R EVANS. Urban congestion survey 1976: traffic flows and speeds in eight towns and five conurbations. Department of the Environment, TRRL Report SR 438. Crowthorne, 1976 (Transport and Road Research Laboratory).. HILLEN, S M. Urban congestion study Interim Report (Thirteen towns and cities in England -- excluding London). Traffic Advisory Unit 1978 (Department of Transport). 12

16 N MANCHESTER,~R.Merse y ".'arrington artinaton TRAFFORD WARRINGTON Lymr ~P1 incham Mere Knutsford 4km I Motorway junction m == == B= == 'B' road "B' road subject to the control Motorway Waterway 'A" road Built-up area BBm mmm 'A' road subject to the control SP1 Survey point Fig.1 MAIN ROAD NETWORK IN THE WARRINGTON/NIANCHESTER AREA

17 0 Z o o o co m ~ ~ ~ o o ~ o o o ~ ~ 0 f ~" o3 /,,~.- ii:i! II Q I i,, "~ ~ L,-..,~,,~-' /,~, # I. 6gLS8 E >-.J It. o >,,, I- E, E~ ']... II If II 0 UJ "r" I-- Z 0 0..a E 0 N ii

18 MANCHESTER (0) WARRINGTON I Lvmm Altrincham A56 M56,% Mere Q mxi m m m Motorway junction Road containing lorry control 'B' road Knutsford (+5) Change in 12-hour flow of HGVs (+ indicates increase in flow) 0 4kin I I Fig.3 EFFECT OF THE LYMM CONTROL ON THE FLOW OF HGVs ON THE ROAD NETWORK (12-hour weekday flows)

19 Neg. no. R134/79/7 Plate 1 A6144: THE APPROACH TO LYMM VILLAGE CENTRE FROM THE SOUTH-WEST / t ' r Neg. no. CR 160/79/3 Plate2 A6144: THE BRIDGE OVER THE BRIDGEWATER CANAL NORTH OF LYMM VILLAGE CENTRE

20 ... a! Neg. no. CR 135/79/12 Plate3 A6144, CARRINGTON LANE, BETWEEN CARRINGTON AND THE A56 AT SALE J! i Neg. no. R 84/79/1 Plate4 B5158, FLIXTON ROAD, URMSTON, BETWEEN CARRINGTON AND THE M63 (675) Dd ,400 4/80 HPLtdSo'ton G1915 PRINTED IN ENGLAND

21 ABSTRACT EFFECTS OF A LORRY CONTROL AT LYMM, CHESHIRE: A W Christie andjprudhoe: Department of the Environment Department of Transport, TRRL Supplementary Report 566: Crowthorne, 1980 (Transport and Road Research Laboratory). TRRL has monitored a lorry control at Lymm, Cheshire which has diverted some 220 heavy lorries per day, many carrying dangerous loads, away from the narrow, tortuous and hilly roads through the village. Although the main aim of the control is to reduce the possibility of major accidents involving large vehicles carrying hazardous loads through Lymm it has not proved possible to evaluate its effect on the probability of such accidents occurring there or elsewhere. The diverted vehicles now use better, but longer, routes at an extra cost to operators averaging about 1.50 per one-way trip and totalling nearly 100,000 annually. They now pass more dwellings than formerly but, in general, the individual HGV flow increases are less than the individual flow decreases and are on roads which already carried much greater total traffic flows. ISSN ABSTRACT EFFECTS OF A LORRY CONTROL AT LYMM, CHESHIRE: A W Christie andjprudhoe: Department of the Environment Department of Transport, TRRL Supplementary Report 566: Crowthorne, 1980 (Transport and Road Research Laboratory). TRRL has monitored a lorry control at Lymm, Cheshire which has diverted some 220 heavy lorries per day, many carrying dangerous loads, away from the narrow, tortuous and hilly roads through the village. Although the main aim of the control is to reduce the possibility of major accidents involving large vehicles carrying hazardous loads through Lymm it has not proved possible to evaluate its effect on the probability of such accidents occurring there or elsewhere. The diverted vehicles now use better, but longer, routes at an extra cost to operators averaging about 1.50 per one-way trip and totalling nearly 100,000 annually. They now pass more dwellings than formerly but, in general, the individual HGV flow increases are less than the individual flow decreases and are on roads which already carried much greater total traffic flows. ISSN