Peter Bonsall

DRIVER RESPONSE TO VARIABLE MESSAGE SIGNS: A STATED PREFERENCE INVESTIGATION

Abstract This paper uses a Stated Preference approach to undertake a detailed assessment of the effect on drivers’ route choice of information provided by variable message signs (VMS). Although drivers’ response to VMS information will vary according to the availability of alternative routes and the extent to which they are close substitutes, our findings show that route choice can be strongly influenced by the provision of information about traffic conditions ahead. This has important implications for the use of VMS systems as part of comprehensive traffic management and control systems. The principal findings are that the impact of VMS information depends on: the content of the message, such as the cause of delay and its extent; local circumstances, such as relative journey times in normal conditions; and drivers’ characteristics, such as their age, sex and previous network knowledge. The impact of qualitative indicators, visible queues and delays were examined. It was found that not only is delay time more highly valued than normal travel time, which is to be expected, but that drivers become more sensitive to delay time as delay times increased across the range presented.

VALIDATING THE RESULTS OF A ROUTE CHOICE SIMULATOR

A new class of herbicidal compounds consisting of 1-alkyl- and 1,1-dialkyl-3-(3-substituted-4-nitro-5-iso-thiazolyl)ureas in which the 3-substituent consists of alkyl, alkoxy, alkylamino, alkylthio, alkylsulfinyl, and alkylsulfonyl exhibits preemergence and postemergence herbicidal activity, controlling effectively the growth of a wide spectrum of grassy and broad-leaved plant species. The synthesis of a representative member of this class is described in detail, and its utility is exemplified.

Understanding traffic systems : data, analysis and presentation

Contents: Introduction: Introduction and context The traffic analysis process. Basic Traffic Theory: Basic traffic flow theory Theories of interrupted traffic flow Theories of area-wide traffic flow. Data Capture: Principles of survey planning and management Experimental design and sample theory Vehicle counting and classification surveys Traffic condition data Environmental impacts. Traffic Studies: Intersection studies Origin-destination and route choice studies Traffic generation and parking studies Road safety studies. Data Analysis and Modelling: From data to information Statistical analysis Statistical modelling. Appendix A: Statistical tables Appendix B: Database of vehicle speeds on residential streets References Index.

Drivers’ response to parking guidance and information systems

This paper reviews published evidence of the effects of dynamic information and guidance on drivers’ choices of car parks. A major conclusion is that overall response levels to dynamic information are much lower than might be expected. Behavioural generalizations are difficult due to the varying nature of the systems being developed as well as the studies that have been undertaken. The lack of conclusions able to be generalized highlights the complexity of the parking choice process. Wide variations in awareness and usage rate were found between different groups of drivers, including age, gender, trip purpose and frequency. Explanations of the responses of drivers to PGI systems can be made by considering the drivers’ level of knowledge, their ability to interpret information as well as their preference for different types of information.

Legislating for modal shift: background to the UK's new transport act

This paper reviews the background to the recent changes in the U.K. transport policy emanating from the publication and passage of a Transport Bill in December 1999 (HOC 1999). After the review, some of the Transport Bills key proposals, such as public transport policy and privatization, are discussed in detail.

CAN INDUCED TRAFFIC BE MEASURED BY SURVEYS

This paper addresses the feasibility of measuring induced traffic by means of appropriately designed surveys. The problems which confront any attempt to measure induced traffic are described and discussed. They include: inherent variability of traffic data, difficulty in establishing what would have happened in the absence of the scheme, uncertainties in the attribution of cause and difficulty in determining the most appropriate time to conduct surveys. Some of these problems have no solution while others can be reduced with an appropriate programme of surveys and control studies. Calculations are made of the sample sizes required to achieve various levels of target accuracy. It is concluded that, given an appropriate programme of traffic counts including control studies and extensive screenlines, it should be possible at relatively modest cost and with reasonable precision, to measure the increases in traffic associated with a scheme and to identify how much of that increase is due to rerouteing. Any further disaggregation of this extra traffic into that which is due to change of mode, change of destination and increased frequency, is much more problematic. The basic traffic counts would need to be supplemented by a programme of public transport surveys, registration plate marking and/or roadside interviews, which would add very considerably to the cost of the exercise. However, even with considerable expenditure, adequate precision may be difficult to achieve and attribution of cause impossible to make.

What makes a car-sharer?

Information from various sources, but most specifically from the YORKSHARE car-sharing schemes, is brought together in an analysis of public reaction to, and participation in, a car-sharing scheme with centralised matching of applicants. The importance of various attributes of the sites, of the individuals and of the scheme organisation are assessed and conclusions are drawn.The motivation of individual participants is analysed and is seen to vary from one person to another depending to some extent on their circumstances, but the universal importance of some features, notably cost savings, is revealed.

Employer Expectations for Commuting and Business-Related Travel in an Environment Rich in Information and Communication Technologies

The collection and the analysis of data on working from home (teleworking) and on the use of information and communication technologies (ICT) to substitute for business travel are described, and conclusions are drawn. Data were collected from senior management by using a web-based questionnaire incorporating several innovative features; in addition to data on current and expected levels of home-working and business travel in a range of ICT scenarios, data were collected on the respondents perception of the impact of different factors on future levels of these activities. Also, to test the robustness of respondent opinions, the impact of alternative versions of a briefing text—one positive and one negative about the role of ICT—on respondent expectations was evaluated. Analysis revealed that a number of factors that are often ignored or taken as constant would be influential in the future levels of homeworking and business travel. Generally, issues of cost appeared to be much less influential than the spe...

The changing face of parking-related data collection and analysis: The role of new technologies

Current trends in requirements for parking related information and in the availability of data are reviewed. Important influences include the increased need for data to assist in the efficient operation and management of parking stock and to assess the impact of parking on the local network and economy. New sources of data are described, particular attention being given to the availability of data as a byproduct of parking management systems and computerised enforcement systems. The use and performance of audio, video and data loggers in parking surveys is discussed as is the role of computers in questionnaire surveys. New methods of analysis involving spreadsheets, graphics and analysis software, links with databases and simulation models are outlined.

A short-cut method for strategy optimisation using strategic transport models

This paper describes a methodology which permits optimal strategies for strategic transport models to be found by use of a limited number of model runs together with regression modelling of the resulting response surface. Typically, it will be the case that the number of policy variables is sufficiently large that the strategic model cannot be run for all possible combinations of their levels. Furthermore it can be very difficult to interpret the results from a large number of model runs where there are a lot of policy variables changing levels between runs. The proposed methodology models the response surface specifically in the locality of the optimum, thereby greatly clarifying what policy combinations should be further tested with the strategic model. A case study, for the city of Edinburgh, indicates that this methodology can identify improved strategies compared to conventional methods, even when the number of model runs used are far fewer than with the conventional methods.