National Multi-Modal Travel Forecasts. Literature Review: Aggregate Models

This paper reviews the current state-of-the-art in the production of National Multi-Modal Travel Forecasts. The review concentrates on the UK travel market and the various attempts to produce a set of accurate, coherent and credible forecasts. The paper starts by a brief introduction to the topic area. The second section gives a description of the background to the process and the problems involved in producing forecasts. Much of the material and terminology in the section, which covers modelling methodologies, is from Ortúzar and Willumsen (1994). The paper then goes on to review the forecasting methodology used by the Department of Transport (DoT) to produce the periodic National Road Traffic Forecasts (NRTF), which are the most significant set of travel forecasts in the UK. A brief explanation of the methodology will be given. The next section contains details of how other individuals and organisations have used, commented on or attempted to enhance the DoT methodology and forecasts. It will be noted that the DoT forecasts are only concerned with road traffic forecasts, with other modes (rail, air and sea) only impacting on these forecasts when there is a transfer to or from the road transport sector. So the following sections explore the attempts to produce explicit travel and transportation forecasts for these other modes. The final section gathers together a set of issues which are raised by this review and might be considered by the project

National Multi-Modal Travel Forecasts. Literature Review: Aggregate Models

This paper reviews the current state-of-the-art in the production of National Multi-Modal Travel Forecasts. The review concentrates on the UK travel market and the various attempts to produce a set of accurate, coherent and credible forecasts. The paper starts by a brief introduction to the topic area. The second section gives a description of the background to the process and the problems involved in producing forecasts. Much of the material and terminology in the section, which covers modelling methodologies, is from Ortúzar and Willumsen (1994). The paper then goes on to review the forecasting methodology used by the Department of Transport (DoT) to produce the periodic National Road Traffic Forecasts (NRTF), which are the most significant set of travel forecasts in the UK. A brief explanation of the methodology will be given. The next section contains details of how other individuals and organisations have used, commented on or attempted to enhance the DoT methodology and forecasts. It will be noted that the DoT forecasts are only concerned with road traffic forecasts, with other modes (rail, air and sea) only impacting on these forecasts when there is a transfer to or from the road transport sector. So the following sections explore the attempts to produce explicit travel and transportation forecasts for these other modes. The final section gathers together a set of issues which are raised by this review and might be considered by the project

The Effect of Rail Journey Time Improvements: Some Results and Lessons of British Experience Relevant to High Speed Rail Forecasting.

This paper discusses the British experience of forecasting the effect of journey time reductions on the demand for rail travel. Its purpose is to discuss results and methodologies from the British context which may be appropriate to other contexts, and particularly to forecasting the demand for new high speed rail services. Two areas of research are selected for discussion: aggregate econometric models of rail demand and Stated Preference choice models. It is concluded that the results derived from one context may not be as transferable as one might wish to some other situation and that it is important to obtain a better understanding of the factors influencing journey time elasticities. Both of the demand analysis methodologies discussed could contribute to an improved understanding whilst an attraction of the Stated Preference approach is that it lessens the need to transfer results from one context to another

Measuring the structural determinants of urban travel demand

To be best prepared for tomorrow's cities we need to forecast urban travel demand. To this end, this study calibrates an urban travel demand model, which uses the principal structural variables that have been identified in the literature. It uses a robust econometric method, which has been little applied in the sphere of transportation. The results show that two variables stand out from the others: the user cost of transport - by private car and public transport - and urban density. It is surprising, but explicable with the available data, that the demand functions estimated for a given country are independent from the group of countries to which it belongs.Urban travel ; Demand estimation ; Urban density ; Travel cost

Cycling & Urban Commuting: Results of Behavioural Mode and Route Choice Models

The research reported here was undertaken as part of an Economic and Social Research Council Project (R000237103) entitled Cycling and Urban Mode Choice. The scope of the study is entirely commuting within an urban context. The objectives of the study were: • to better understand the interactions between car, bus, cycle and walk in an urban context and to explain observed variations in cycle trip rates across towns. • to be able to forecast the effect of a range of improvements to cycling facilities on mode choice • to use the estimated models to evaluate some actual schemes • to provide end users (eg consultants, local authorities, cycling organisations) with a tool to determine the effect of policy measures. In particular, to create models which will enhance the performance of strategic, integrated transport studies. The objectives of this paper are: • to describe the methodology that was used to examine cycling within an urban mode choice context • to outline the collection of data required to estimate behavioural models • to report the results of the estimated mode and route choice models • to provide illustrations of how the model can be used to appraise improvements to cycle facilities and cycling conditions. The structure of this paper is as follows. Section 2 gives a brief overview of the policy context of work on cycling in the UK and previous work in the area. Section 3 describes the methodology used to collect the Revealed Preference (RP) and Stated Preference (SP) data necessary for the model. Section 4 describes the data that was collected. Section 5 gives details of the development of the model and some empirical results from the model that was developed. Section 6 illustrates how the model could be used to appraise improvements in cycle facilities and cycling conditions. Section 7 draws some conclusions from the work

Travel Budgets – A Review of Evidence and Modelling Implications.

This paper reviews the empirical data that has been put forward as evidence for the feasibility of direct forecasts of the average amounts of time and money allocated to travel, and the alternative model Craneworks wMch have been designed to exploit such forecasts. It is concluded that the evidence for the stability of aggregate travel behaviour from analyses of cross-sectional data has not yet been reconciled with the variations shown over time

Post-Construction Evaluation of Traffic Forecast Accuracy

This research evaluates the accuracy of demand forecasts using a sample of recently-completed projects in Minnesota and identiÞes the factors inßuencing the inaccuracy in forecasts. The forecast traffic data for this study is drawn from Environmental Impact Statements(EIS), Transportation Analysis Reports (TAR) and other forecast reports produced by the Minnesota Department of Transportation (Mn/DOT) with a horizon forecast year of 2010 or earlier. The actual traffic data is compiled from the database of traffic counts maintained by the Office of Traffic Forecasting and Analysis section at Mn/DOT. Based on recent research on forecast accuracy, the (in)accuracy of traffic forecasts is estimated as a ratio of the forecast traffic to the actual traffic. The estimation of forecast (in)accuracy also involves a comparison of the socioeconomic and demographic assumptions, the assumed networks to the actual in-place networks and other travel behavior assumptions that went into generating the traffic forecasts against actual conditions. The analysis indicates a general trend of underestimation in roadway traffic forecasts with factors such as highway type, functional classiÞcation, direction playing an inßuencing role. Roadways with higher volumes and higher functional classiÞcations such as freeways are subject to underestimation compared to lower volume roadways/functional classiÞcations. The comparison of demographic forecasts shows a trend of overestimation while the comparison of travel behavior characteristics indicates a lack of incorporation of fundamental shifts and societal changes.Minnesota, Minneapolis, Travel Demand Model, Transportation Planning, Forecasting

Review of fares elasticities in Great Britain

INTRODUCTION Empirical analysis of the behavioural impact of a wide range of travel variables has been conducted extensively in Britain over the past forty years or so. With the likely exception of the value of travel time (Wardman, 2001), the most widely estimated parameters have been price elasticities of demand and in particular public transport fare elasticities. The wealth of available evidence provides an excellent opportunity to obtain greater insights into fare elasticities and their determinants. There have been numerous notable reviews of price elasticities (Ely, 1976; TRF&, 1980; Goodwin and Williams, 1985; Goodwin, 1992; Oum et al, 1992; Halcrow Fox et al., 1993; Wardman, 1997; Nijkamp et al., 1998; Pratt, 2000; De Jong and Gunn, 2001; Graham and Glaister, 2002; VTPI, 2003). The unique features of this study are that it covers a much larger amount of public transport evidence and a broader range of issues than previous reviews and, more significantly, it has developed a model to explain variations in fare elasticities across studies. This review covers 902 public transport fare elasticities obtained from 104 studies conducted in Britain between 1951 and 2002. The markets covered are inter-urban rail travel, suburban rail travel, urban bus travel and London underground

From mode choice to modal diversion: A new behavioural paradigm and an application to the study of the demand for innovative transport services

We analyse past research efforts that focus on modal diversion in the transport sector, as opposed to the classical mode choice concept, showing the added value of this alternative framework that emerges from the existing scientific literature. The modal diversion paradigm is then used to assess the relative importance of the technical performances of transport services on one hand and of the subjective factors of its potential users on the other, when forecasting the use of a new means among a group of white-collars working in a French research institute. We quantitatively show that multimodal habits and cognitive attitudes have an importance that is in general not negligible for this group, compared to that of the transport services performances, even if only these latter are routinely considered by engineers and planners. Beyond this, we find that the role of self-related factors further increased when the group was less familiar with the technological background and the subsequent operation of the new system, such as in the case of demand responsive transport service

The demand for urban transport: An application of discrete choice model for Cadiz

The study of the demand for transport has among others applications, the valuation of travel time saving that is a very important question in cost-benefit analysis, and to adopt transport policy tools. Since McFadden developed a discrete choice model for travel demand, it has usually been the application of this model to study the individual behaviour when he has to choice among transport modes. Citizens of big cities have to face traffic congestion; pollution, wasted time in travels and fuel, noise, stress and accidents are the costs imposed by congestion to society, elements that reduce the quality of life in cities. Public transport is a real alternative to private transport that is socially less expensive, for this reason this paper tries to forecast travel demand for public transport in Cadiz when travelling have to choice between public or private transport, using a discrete choice model. The results of this analysis (travel demand, value of time, elasticities) can be used to design transport policies that could reduce congestion.