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This working paper is one of a series (WP 252, 253, 254, 255, 274, 275), describing work undertaken under contract to TRRL investigating design guidance for pedestrian areas and footways to satisfy the needs of disabled and elderly people. This working paper reports on fieldwork conducted with disabled people in Leeds to investigate movement distances; assessments of surface conditions including gaps, undulation, gradients, camber and friction; and assessments of bus shelter seating.

This working paper describes a study of the variability of journey times of a panel of fifteen commuters using one north London radial corridor, over a total of seven weeks in the spring and summer of 1987. The objectives were to gain preliminary information on the extent of journey time variability and on the commuters* perception of and responses to the variability they experienced. The procedure for selecting the panel and contacting them is described, together with the data collection method, which consisted principally of panellists using tape recorders in their cars to record the time at which fixed points along the route were passed on each day's journey to work. Early or late arrival and its consequences in relation to the day's tasks were recorded at the destination. Analyses are presented of the distributions of times of complete and partial journeys, of the relationship between journey duration and variability and of the effects of diversion in response to perceived traffic conditions. The safety margins needed to ensure given percentages of punctual arrivals were estimated and contrasted with those from previous studies. Further analyses are presented indicating the general unimportance of punctuality for these panellists, the effects of significant lateness when it did occur, and of the panellists' ability to predict their arrival times in advance. A study of highway link travel time variability and its causes was also carried out for cars at the a same time in the same corridor. The methodology, surveys and data processing of this parallel study are set out in ITS Working - Paper 278, and the results and analysis in ITS Working Paper 279.

Firms in inner areas of Leeds and London were surveyed to determine the type, extent and severity of their transport problems. The problems were compared with tlose of firms in outer control areas of both cities. The important inner area problems were: congestion and delays on the journey to work, on business and visitor trips, and on commercial vehicle trips; inadequate on-site and on-street parking at the firm and at the destination of business trips; public transport difficulties for the journey to work; on-site delays for commercial vehicles; and on-street loading.Altiough firms in all areas experienced similar types of problem, the effect of congestion and parking WaS more severe in the inner areas, and as expected problems were more severe in London than in the corresponding area of Leeds. Solutions applicable to the inner areas are therefore likely to be appropriate elsewhere. The most common effect of problems was lost time. There were also cases of reduced efficiency, lost business, vehicle scheduling difficulties and staffing implications such as turnover and recruitment and staff dissatisfaction. Management had difficulty costing the effects of problems; however, when estimates were made the costs incurred were often considerable. Problems were, for the most part, local or site specific, and solutions are likely to be found within the study areas or at individual firms. However, in the case of congestion and of parking availability away from the firm the problems are more widespread, suggesting that solutions need to extend beyond the study areas.

1.1.1 Any new road, road improvement or traffic management\ud scheme could affect pedestrian journeys in its locality or\ud elsewhere. Some journeys may be affected directly, with\ud severance caused where the new road or road improvement cuts\ud across a pedestrian route, others may be affected indirectly with\ud a new road causing changes in traffic levels elsewhere. To\ud enable effects on pedestrians to be given proper weight when\ud decisions are taken, techniques are required that forecast the\ud effects of the scheme on the number and quality of pedestrian\ud journeys. This is particularly true in urban areas, since\ud effects on pedestrians may be one of the main benefits or\ud disbenefits of measures to relieve urban traffic.\ud \ud (Continues..)

BACKGROUND\ud \ud This study was commissioned by the Civic Trust to identify new approaches to traffic management solutions for Sowerby Bridge. The objective of the overall study was to identify low cost, innovative solutions to problems created by high volumes of traffic using the A58. This road is the main shopping street in Sowerby Bridge. In our brief it was stressed that any new road construction, such as a by-pass, was not a feasible or acceptable solution due to the severe vertical gradients surrounding Sowerby Bridge. \ud \ud The town is on the brink of a major programme of regeneration. A nationally important canoe slalom course has been created, the riverside mill area fronting onto the River Calder is being developed for commercial and leisure use, and there is a proposal to reopen the Rochdale Canal. In view of this it is essential to ensure that traffic on the A58 is managed so as to minimise its effect on the environment and trade, without adversely affecting local access. In writing our report we have separated the problem and solution identification stages. The solution identification stage is reported in Working Paper 263 (Hopkinson et al 1988b). The final stage of our study, which involves presenting our final solutions back to the users of Sowerby Bridge for comment, is to be reported in a forthcoming report, WP 265 (Hopkinson et al, 1988c).

This Study of two firms in Sheffield city centre has been carried out under a contract with LTR2 Division of the Department of Transport, dated 28th March 1980. The Department of Transport has been interested for some time in various aspects of car-sharing, and the impact on car sharing of different work hour arrangements, and had previously carried out surveys of car-sharers in Government offices at Longbenton, Newcastle upon Tyne (TAU 1977) and Llanishen, Cardiff (TAU 1979) where flexible working hours were in operation. This study was designed as a continuation of those studies, in a city centre area where car parking was severely restricted. The prime objective was to measure levels of car sharing in locations with higher levels of public transport provision but more restricted parking, for later comparison with the results from Longbeutzen and Llanishen. The need for the study was occasioned by the desire to know more about the factors which influence people to share cars, and the characteristics of existing spontaneously formed car-sharing arrangements and participants. To obtain this information, details of the travel and work habits of the workforce concerned had to be collected and analysed. It was considered useful to try to establish any characteristics common to ad-hoc car-sharing participants as a basis for suggesting possible causal factors. The form of the study, in terms of the type of data collected, and its subsequent tabulation, was largely shaped by the need to provide data comparable to that collected in the aforementioned studies at Longbenton and Llanishen. Other work in the Institute on the prediction of demand for car- \ud sharing (Bonsall, 1980) and the establishment of experimental carsharing schemes (Bonsall et al, 1980) provided a useful basis for comparing the survey requirements for identifying potential car-sharers with those for identifying existing ones.

Twelve firms from the Holbeck Hunslet Industrial Area of inner Leeds were surveyed early in 1980 to determine the type, extent and severity of their transport problems. In order to compare and contrast these problems with those of firms located in an outer urban area twelve firms in the Stanningley area of Leeds were also surveyed. \ud \ud The samples have been treated as a series of case studies and the results for individual firms are available from the authors. This paper presents the survey results aggregated for each of the study areas. \ud \ud The predominant inner area problems revealed during the surveys, and amenable to solution by local authorities or the firms themselves, included: congestion and delays on the journey to work, on business trips and on commercial vehicle trips; inadequate parking at the firm; public transport difficulties for the journey to work; personal trips during the day; manoeuvring difficulties into and within premises for commercial vehicles; and delays during loading and unloading. \ud \ud Taken together, the results of the five surveys which were conducted at each firm suggested that in terms of the number of firms affected, and the degree of severity, transport problems did not seriously disrupt firmsr operations. Nevertheless they resulted in considerable lost time and in many cases a direct cost. There was a general inability of management to place a money cost against the problems which they mentioned and consequently there is the possibility that the impact of problems may be understated by local authorities. \ud \ud With the exception of parking at the firm, and to some extent manoeuvring difficulties, firms in Stanningley suffered similar problems to those in Holbeck Hunslet. In the case of Leeds it could not be concluded that inner area firms experienced different types of problems, and to a greater degree of severity, than firms located elsewhere in the urban area. Solutions applicable to the inner area are therefore, likely to be appropriate elsewhere. \ud \ud This paper is the first in a series reporting the results of surveys of samples of firms in Leeds and London.

The report evaluates the extent to which representative samples of manu- facturing and service firms drawn from the inner and outer London areas of South Shoreditch and Brimsdown respectively would be affected by proposed bans on 16 ton and 24 ton GVW commercial vehicles within Greater London.\ud \ud The proportion of commercial vehicle trips to and from South Shoreditch firms affected by the bans would be low and one-quarter of the firms would be affected by a 16 ton GW ban. One in five trips to and from Brimsdown firms is currently made by a vehicle in excess of 16 ton GVW, and two-thirds of the sample of firms would be affected. The majority of affected movements are by suppliers' vehicles rather than firms' own fleets. \ud \ud Three firms particularly likely to be affected were examined in more detail, and the implications of their changing to lighter vehicles investigated. A weight-specific 16 ton GVW ban would impose annual operating cost increases on all firms if they were to maintain existing levels of service with their own vehicle fleets. Under a 24 ton GVW ban two firms would incur cost increases while, for the operations considered, there would be a saving in annual operating costs for the third. The assumption that regulations governing vehicle dimensions and carrying capacity remain unaltered is crucial to the conclusions. \ud \ud Night time 16 ton and 24 ton GVW bans would affect a minority of firms, although the duration of the ban would be important. Weekend bans would not significantly affect the firms.

This paper presents the results-of a study of peak period travel times and potential causal factors conducted over a one year period on five radial routes. It describes the hypotheses tested and the survey design adopted and then presents results for inter-vehicle variation in travel time within 250 15 minute periods and for inter-period variation based on 1018 moving observer runs. Moving observer results are found to depend on flow over the previous half hour, and a modified time series analysis used to demonstrate this is outlinzd. The contriuhtion of other explanatory variables is also presented.

Previous studies of inner city manufacturing and service firms and studies of industrial relocation are examined to determine the problems of operating in inner areas, the factors causing firms to relocate, and the criteria which determine the choice of new site. These are related to the issues of retaining existing inner area firms and attracting new ones. \ud \ud Much of the previous work is limited in scope, largely qualitative, and frequently at a level of aggregation which makes identification of particular problems or factors difficult. Existing inner city firms perceive the transport problems of their own operations and of their employees as a major disadvantage of their present location, but there is a lack of quantified information on the extent and relative importance of these problems, and whether they are more severe for inner city firms. Transport issues in themselves are not one of the prime reasons causing firms to relocate, although the influence on availability of suitable labour is more significant. At a regional level transport is not one of the most important criteria in the choice of location, but as a determinant of site at the local level it is mentioned frequently enough to warrant further study. A number of other factors involved in these decisions are to a greater or lesser extent related to transport. \ud \ud To place firms' transport operations in a wider context transport costs, industrial traffic generation, and the effect of some forms of control are discussed.

1.1.1 Any new road, road improvement or traffic management\ud scheme could affect pedestrian journeys in its locality or\ud elsewhere. Some journeys may be affected directly, with\ud severance caused where the new road or road improvement cuts\ud across a pedestrian route, others may be affected indirectly with\ud a new road causing changes in traffic levels elsewhere. To\ud enable effects on pedestrians to be given proper weight when\ud decisions are taken, techniques are required that forecast the\ud effects of the scheme on the number and quality of pedestrian\ud journeys. This is particularly true in urban areas, since\ud effects on pedestrians may be one of the main benefits or\ud disbenefits of measures to relieve urban traffic.\ud \ud (Continues..)

This Report compares the results of the Before and After studies of some effects of the introduction of wheel clamps in Central London. Park and Visit and Vehicle Following studies were carried out in both cases, with Registration Number and Business Interview surveys taking place in the Before study only. \ud \ud The two areas of Central London which were studied comprised an area of Mayfair in which wheel clamps were to be introduced, and an area of Bloomsbury in which they were not. The surveys were designed to identify changes related to congestion and ease of access effects and so complement a series of surveys conducted by consultants for TRRL. \ud \ud The report describes each survey methodology, and presents the results of the Park and Visit and Vehicle Following surveys. A significant reduction in journey times is identified in Bloomsbury but not in Mayfair. However, the confidence intervals for Mayfair were too wide to determine whether the change in travel times in Bloomsbury was significantly different from the change in Mayfair. Significant reductions in search time are recorded in both areas, and a significant reduction in search plus walk time in Bloomsbury. An increase in empty meter spaces is identified in Mayfair and these findings from the Park and Visit surveys are supported by evidence from the Vehicle Following survey which suggests a drop in the degree of searching for meter spaces in Mayfair. \ud \ud Note: Further details of the survey are to be found in the associated technical note to this report (May et al, 1984b) and the individual reports on the Park and Visit and Vehicle Following surveys (May et al, 1984a).

Nineteen firms from the South Shoreditch area of LB Hackney were surveyed in Spring 1980 to determine the type, extent and severity of their transport problems. In order to compare and contrast these problems with those of firms located in an outer urban area, twenty firms in the Brimsdown area of LB Enfield were also surveyed. This paper presents the aggregated survey results for each study area. \ud \ud The most important inner area problems included : congestion and delays on the journey to work, on business and visitor trips, and on commercial vehicle trips; inadequate on-site and on-street parking at the firm and at the destination of business trips; public transport difficulties for the journey to work; on-site difficulties for commercial vehicles; delays during loading; and on-street loading. \ud \ud The most commonly reported effect of problems was lost time, however there were also instances of reduced efficiency, lost business, vehicle scheduling difficulties and staffing implications such as turnover and recruitment, staff dissatisfaction, the necessity to provide assistance for the journey to work or personal trips, ,and adjustments to working hours. There was a general inability of management to place a money cost against the problems which they mentioned although when estimates were made the costs were often considerable, and consequently there is the possibility that the impact of problems may be understated by local authorities. \ud \ud Firms in Brimsdown suffered similar types of problem to firms in South Shoreditch, and in most cases to a similar degree of severity. Solutions applicable to the inner area are therefore likely to be appropriate elsewhere.\ud \ud This paper is the second in a series reporting the results of surveys of samples of firms in Leeds and London.

This report, produced for the Transport and Road Research Laboratory, summarises the results of an extensive literature search in two areas of pedestrian research:\ud \ud (I) Estimating the Number of Pedestrian Journeys \ud \ud (2) Pedestrian Amenity \ud \ud The report identifies gaps in current knowledge from the revealed literature and makes recommendations for best practice. Research proposals are made, to help alleviate such revealed gaps, in a companion report.

This paper describes the design of a survey to measure variations in travel time and their possible causes and to develop cost effective travel time survey instruments. After describing the background and objectives of the study it reviews in turn the uses to which travel time data can be put and the resulting survey requirements, the factors which might cause variations in travel time, and the available survey methods. The survey strategy outlined in the final section is based on these reviews. It concentrates on inbound peak period travel times over five radial routes in Leeds, and uses number plate matching to measure inter-vehicle variation, and moving vehicle observer methods to measure inter-period variation. Two other methods are also employed. The surveyperiod is spread over 14 months to identify seasonal effects, but uses a Latin Square design to reduce the scale of the data collection task.

INTRODUCTION\ud \ud This working paper is the third in a series of three on the control of congestion at highly saturated signalised intersections. The other papers in the series are: \ud \ud WP 220 Control of Congestion at Highly Saturated Signalised Intersections: 1 - Survey Methods\ud \ud WP 221 Control of Congestion at Highly Saturated Signalised Intersections: 2 - Experiments at an Isolated Junction. \ud \ud After a brief explanation of the purpose of the study, and the part played by the Rama 4 experiments, this paper describes how the input data for the experiments was collected, updated and prepared for use in standard signal setting programs. The conduct of the actual experiment is then described followed by results and conclusions thereof.

Any new road, road improvement or traffic management\ud scheme could affect pedestrian journeys in its locality or\ud elsewhere. Some journeys may be affected directly, with\ud severance caused where the new road or road improvement cuts\ud across a pedestrian route, others may be affected indirectly with\ud a new road causing changes in traffic levels elsewhere. To\ud enable effects on pedestrians to be given proper weight when\ud decisions are taken, techniques are required that forecast the\ud effects of the scheme on the number and quality of pedestrian\ud journeys. This is particularly true in urban areas, since\ud effects on pedestrians may be one of the main benefits or\ud disbenefits of measures to relieve urban traffic.\ud \ud (Continues..)\ud

In early 1983 York City Council and North Yorkshire County Council commissioned the Institute for Transport Studies to carry out a study of cycling in York. The terms of reference were to: \ud \ud Include an origin and destination survey of current movements by trip purpose and an assessment of future demand, indicating the likely mode from which any transfer will occur; \ud \ud Identify problem areas following discussions with various cycling groups and a study of accident statistics; \ud \ud Take into consideration any previous decisions of the City Council for investigation;\ud \ud Assess the appropriateness of the recommended standards for cycle facilities to a compact urban area; \ud \ud Propose various solutions to problems where appropriate, assess the effect on other road users, and formulate a basic cycling plan for York. \ud \ud Propose various solutions to problems where appropriate, assess the effect on other road users, and formulate a basic cycling plan for York. \ud \ud The Institute for Transport Studies at the Univeristy of Leeds was appointed to carry out the study with Professor A.D. May as the Director of the Study and Mr. D.A. Waring as Research Engineer. Work commenced on this project in June 1983 and was completd in May 1984.\ud \ud The recommendations arising from the study are contained in a separate Summary Report, available from the Institute as Working Paper 175.

Using Wakefield as a case study, a method was developed of testing the effects on traffic of several different work journey rescheduling strategies. The method consisted essentially of assigning a series of six 0-D matrices to the Wakefield network, each matrix representing the trips for consecutive 15 minute periods over the morning peak. The six matrices were obtained by firstly disaggregating the l 1/2 hr peak matrix by purpose (into home-based work, commercial vehicle, and other trips) and then disaggregating each of these three matrices by time. This temporal disaggregation was based, for the home based work trips, on employee arrival profiles by zone, and for the CV and other trips on cordon crossing profiles. The different strategies were modelled by making adjustments to the parameters of the employee arrival profiles. Other relevant papers in this series are WP 150 Work Journey Rescheduling : Report of Surveys, and WP 168 Work Journey Reschediuling : Results and conclusions.

1.1 BACKGROUND\ud \ud \ud This study was commissioned by the Civic Trust to identify new\ud approaches to traffic management solutions for Sowerby Bridge.\ud The objective of the overall study was to identify low cost,\ud innovative solutions to problems created by high volumes of\ud traffic using the A58. This road is the main shopping street in\ud Sowerby Bridge. In our brief it was stressed that any new road\ud construction such as a by-pass was not a feasible or acceptable\ud solution due to the severe vertical gradients surrounding Sowerby\ud Bridge.\ud \ud \ud Further, the town is on the brink of a major programme of\ud regeneration. A nationally important canoe slalom has been\ud created; the riverside mill area fronting onto the River Calder\ud is being developed for commercial and leisure use and there is a\ud proposal to reopen the Rochdale Canal. In view of this it is\ud essential to ensure that traffic on the A58 is managed so as to\ud minimise its effect on the environment and trade, without\ud adversely affecting local access. In writing our report we have\ud separated the problem and solution identification stages. The\ud solution identification stage is reported in a companion report\ud (Hopkinson et all 1988b). A further stage of our study which\ud involves presenting our final solutions back to the users of\ud Sowerby Bridge for comment is to be reported in a forthcoming\ud report, WP 265 (Hopkinson et al, 1988c).\ud \ud \ud 1.2 INTRODUCTION\ud \ud \ud This Working Paper describes the methods used and findings from\ud the first stage of our study carried out during October and\ud November 1987 to identify the problems experienced by the users\ud of Sowerby Bridge. Here it is intended to draw conclusions about\ud the approach adopted to elicit people's impressions about\ud problems, the way in which this information was interpreted and\ud the applicability of the method to other situations.\ud

As part of the project for the Transport and Road Research\ud Laboratory concerned with the development of design guidance for\ud pedestrian areas and footways to satisfy the needs of disabled\ud and elderly people, a thorough examination of the literature was\ud required. In addition the literature search was to be\ud complemented by a wide-ranging series of discussions with local\ud authorities, organisations representing the interests of elderly\ud and disabled people, and other interested agencies. This Working\ud Paper sets out the findings of this exercise.\ud \ud \ud The objective of the literature review and the consultations was\ud to identify the key impediments for elderly and disabled people\ud when using pedestrian areas and footways. The current guidelines\ud and standards relating to footways, pedestrianised areas and\ud access to buildings were to be identified and their adequacy\ud commented upon, as were the conflicts such recommendations raise\ud between various groups of disabled people and with able-bodied\ud people. The consultations were intended to provide greater\ud insights into what the literature highlighted, and to suggest\ud possible solutions.\ud \ud \ud The literature review produced over 400 key references and a list\ud of 35 impediments. A more detailed examination of the literature\ud and the consultations reduced this list to six key impediments\ud namely: parking; public transport waiting areas; movement\ud distances; surface conditions; ramps, and information provision.\ud \ud \ud The type and scale of problem created by the above impediments\ud for various groups of disabled and elderly people are discussed,\ud together with their measurement and assessment. The type and\ud adequacy of existing design standards and guidance relating to\ud these impediments are also outlined.

1.1.1 Any new road, road improvement or traffic management\ud scheme could affect pedestrian journeys in its locality or\ud elsewhere. Some journeys may be affected directly, with\ud severance caused where the new road or road improvement cuts\ud across a pedestrian route, others may be affected indirectly\ud with a new road causing changes in traffic levels elsewhere. To\ud enable effects on pedestrians to be given proper weight when\ud decisions are taken, techniques are required that forecast the\ud effects of the scheme on the number and quality of pedestrian\ud journeys. This is particularly true in urban areas, since\ud effects on pedestrians may be one of the main benefits or\ud disbenefits of measures to relieve urban traffic.\ud \ud (Continues..)\ud

1.1.1 \ud \ud The Institute for Transport Studies was invited by the\ud Transport and Road Research Laboratory to submit a research\ud proposal, with costs, aimed at establishing suitable llErgonomic\ud Standards for Pedestrian Areas for Disabled People". The project\ud commenced on 1st July, 1986 and was split into two parts, with\ud part one involving four monthso work over the period to 31st\ud December, 1986 and part two finishing on 30th April, 1988.\ud \ud \ud 1.1.2 \ud \ud The main objectives of the Study laid down in the design\ud brief by the Transport and Road Research Laboratory were:\ud \ud \ud a) To produce a guide to good practice for the design and\ud maintenance of footways and pedestrianised areas;\ud \ud b) To provide, where possible, recommended standards for design\ud and maintenance.\ud \ud \ud The good practice guide and the recommended standards were to be\ud primarily aimed at disabled people and the elderly, but the\ud requirements of the able-bodied were also to be considered, as\ud were conflicts between the needs of different groups of user.\ud The economic implications of implementation and maintenance were\ud also to be detailed.\ud

In order to model the possible effects of rescheduling the work journey on city centre peak period traffic congestion, it was necessary to obtain information about the current employment position in the city centre, and about traffic conditions in the peak period. To this end, a series of surveys were designed and implemented to collect information from a stratified sample of centrally located employers; a sample of their employees; and about traffic conditions between the hours of 07.30 and 09.30 along selected routes leading into the city centre.\ud \ud Problems in running the surveys were encountered and overcome, and the resulting information covered: \ud \ud - Employee numbers, their permitted work hours, and the type of schedule worked per employer. \ud \ud - The Standard Industrial Classification (SIC) of each employer.\ud \ud - Car parking facilities provided by employer. \ud \ud - Bus facilities provided by employer. \ud \ud - Origin of employees' journey to work.\ud \ud - Mode(s) used in employees' journey to work. \ud \ud - Employees' actual arrival at and start work times, together with departure from work time, for the week preceeding the survey. \ud \ud - Personal characteristics of employees. \ud \ud - Structure of employees' households. \ud \ud - Journey times and traffic flows along selected corridors. \ud \ud The data thus collected was used to provide a base situation against which modelled alternative work hour strategies could be tested.

1.1.1 The Institute for Transport Studies was invited by the\ud Transport and Road Research Laboratory to submit a research\ud proposal, with costs, aimed at establishing suitable "Ergonomic\ud Standards for Pedestrian Areas for Disabled People". The project\ud commenced on 1st July, 1986 and was split into two parts, with\ud part one involving four months' work over the period to 31st\ud December, 1986 and part two finishing on 30th April, 1988.\ud \ud \ud 1.1.2 \ud \ud The -objectives of the study laid down in the design\ud brief by the Transport and Road Research Laboratory were:\ud \ud \ud a) To produce a guide to good practice for the design and\ud maintenance of footways and pedestrianised areas;\ud \ud b) To provide, where possible, recommended standards for design\ud and maintenance.\ud \ud The good practice guide and the recommended standards were to be\ud primarily aimed at disabled people and the elderly, but the\ud requirements of the able-bodied were also to be considered, as\ud were conflicts between the needs of different groups of user.\ud The economic implications of implementation and maintenance were\ud also to be detailed.\ud \ud (Continues..)

This working paper is one of a series of three describing\ud research on travel time variability of car drivers using a north\ud London corridor. The objectives of the work described in this\ud report were to determine the amount of variability experienced\ud within short time periods and between time periods, and to\ud explain these variations in terms of simultaneously-recorded\ud traffic factors.\ud \ud \ud This report describes the methodology used, the surveys carried\ud out and the data processing procedures. Data were collected on\ud twelve contiguous links on the A41 between 0730 and 1030 on\ud weekdays in spring and again in summer. Link travel-time\ud distributions for cars were obtained by registration-plate\ud matching using hand-held electronic data loggers. The methods\ud of treatment of spurious matches and outliers, resulting\ud respectively from chance matching of partial registration numbers\ud and from stopping or diverting vehicles, are described. The\ud reasons for selecting particular explanatory traffic variables\ud are presented, together with a description of the methods of data\ud collection.\ud The results of these surveys and their analysis are contained in\ud ITS Working Paper 279. The methodology, data collection\ud procedure and analysis of journey time variability experienced\ud by a panel of car commuters using the same corridor are contained\ud in ITS Working Paper 277.

The report assesses the -development and potential of two individual survey techniques; the Park and Visit and the Vehicle Following surveys. The Park and Visit Survey has its origins in work conducted by Inwood for TRRL in 1966 and is primarily concerned with ease of access effects in terms of search and search plus walk times, when Looking for a parking space. The Vehicle Following surveys, used extensively hy Wright (1975), relate to the degree of searching and hence more directly to the route choice and congestion related effects of parking in city centres. Both surveys can be budgeted at a fairly Low cost and involve the use of small survey teams, over a short period of time. Yet each survey is robust in nature and yields information of a behavioural nature largely omitted from conventional parking usage data collection.

The last decade has witnessed a considerable change in the objectives of urban transport policy and hence in the methods employed for solving transport problems. In particular, there has been a significant switch from high cost additions to the transport infrastructure to low cost measures designed to manage the existing infrastructure more efficiently. Most of the successful developments, however, have been in traffic management techniques, such as bus lanes and mini-roundabouts which have been designed solely to reduce travel time for existing patterns of movement. By contrast, transport management measures, such as fares subsidies and restraint, which are designed to encourage a change in the pattern of travel, have met with far less success. \ud \ud This paper, which is the text of Professor May's inaugural lecture, reviews these developments, discusses some examples of both successful and unsuccessful transport management proposals, and identifies the aspects of these proposals about which there has been greatest concern and uncertainty. It suggests, from this analysis, the changes which need to be made in techniques of prediction, experimental design and policy implementation if the role of transport management is to be more clearly understood.

This working paper describes the results of a study of the variability of travel times and its causes on links of a secti.on of the A41 radial route in north London in the spring and summer of 1987. The objectives were to estimate the extent of variability of travel times of private car users and to explain the observed variability by means of models incorporating a range of traffic factors, including traffic flow, and incorporating seasonal differences. In general the spring was slower and showed more travel time variation between time periods than the summer. slower and more variable links in the spring tended to behave similarly in the summer. The models produced explained around two thirds of the travel time variation between periods, but the explanatory power and explanatory variables differed between links. Blocking of the downstream exit from links was the single variable which was significant in affecting traffic times on most links. \ud \ud

This project is a TRRL research contract, the aim of which is to\ud produce guidance on the design of pedestrian areas and footways\ud for elderly and disabled people. The first part of the project\ud was a literature review and consultation exercise, the objective\ud of which was to identify key impediments for investigation. The\ud second part of the project involved the detailed survey work on\ud the key impediments. This Working Paper reports upon the\ud development of the second part of the project and, in particular,\ud upon the identification of the sample of disabled people to be\ud used in the detailed interview and observation work.\ud The sample identification involved contacting some 3000 disabled\ud people listed in official disability registers, and 250 ablebodied\ud people via on-street interviews. From the disabled sample\ud approximately 500 people were interviewed in order to find out\ud more about their disability and to assess the usefulness of a\ud preliminary disability categorisation system; their activity\ud rate; problems they experience in using pedestrian areas and\ud footways; and their willingness to take part in further stages of\ud the study.\ud \ud \ud From the interviews, a sample of people in each of the revised\ud categories, together with samples of the elderly and the ablebodied,\ud were selected for an observation phase in which those\ud involved were observed completing a movement distance exercise,\ud and using different types of pedestrian facility, in central\ud Leeds .

The paper arises from a recent investigation into the extent to which transport problems affect manufacturing firms and their employees. It summarises the conclusions of that study and notes their implications for the selection and assessment of transport policies designed to assist industry.\ud \ud One of the conclusions is that most problems are local or site- specific; this suggests that local and probably low cost solutions developed by local authorities or by firms themselves may well be more appropriate than programmes of major investment. However, another conclusion is that firms are generally inadequately aware of the effects of their transport problems and the costs to which they give rise; this suggests that the justification even for low cost solutions may not be being made sufficiently apparent to local authorities. These conclusions indicate the need for a more careful assessment of the effects of both high and low cost transport policies on industry. \ud \ud The paper outlines the way in which an analysis of firms' transport problems may be used to develop appropriate solutions and to assess their effects. It discusses some of the problems of such an investigation, using case studies drawn from recent research in Inner London.

This report presents the results of a before study of some effects of the introduction of wheel clamps in Central London. Park and visit, vehicle following, registration number and business interview surveys were conducted in two areas of Central London: Mayfair in which wheel clamps were to be introduced, and Bloomsbury where they were not. The surveys were designed to determine the availability of parking spaces, the extent to which vehicles searched for parking spaces, the time spent doing so and gaining access to destinations, the level of through traffic, and the parking problems perceived by businesses. They were complementary to a series of surveys conducted by consultants for TRRL. \ud \ud The report describes the design and piloting of the surveys, presents the results of the surveys, identifies the levels of change which it will be possible statistically to detect and makes recommendations for the after surveys. In particular it recommends that the park and visit and vehicle following surveys be repeated, and also presents arguments in favour of repeating the business survey and conducting a survey on trade.