Teleworking in the Netherlands: an evaluation of changes in travel behaviour

This article describes the first experiment on teleworking in the Netherlands, and presents the results of an analysis of the impact of teleworking on the travel behaviour of the participants in the experiment and their household members. It was concluded that teleworking has resulted in a significant decrease in the total number of trips by teleworkers (–17%). Peak-hour traffic by car has been reduced even more (–26%). An unexpected result was that the household members of the teleworkers also appeared to travel less than before the experiment.     

A tale of two cities

Land use and transportation mutually affect each other. Unfortunately, most transportation decision making procedures assume that public agencies cannot shape future land use patterns, and that past land use practices unswervingly determine future conditions. In A Tale of Two Cities, the author surveys the correlations between land use policies and travel behavior in two Oregon cities (Portland and Hillsboro).Building on successes the City of Portland has achieved in reducing reliance on the automobile, the author outlines a recent project by 1000 Friends of Oregon, titled Making the Land Use, Transportation, Air Quality Connection (LUTRAQ). According to the author, the purpose of LUTRAQ is to replicate Portland's approach in a more suburban context. Specifically, LUTRAQ is attempting to develop a realistic land use/transportation/demand management alternative to a proposed new bypass freeway and to accurately measure that alternative for its effects on travel demand, land use, air quality, climate change, and other indices. Although LUTRAQ is a project in progress, the author provides preliminary information that suggests the alternative successfully reduces demand for single occupancy automobile travel.     

Disaggregate simultaneous urban travel demand models: A brief introduction

This paper is intended to provide a general background to the two following papers, A Simultaneous Destination and Mode Choice Model for Shopping Trips and Some Estimation Results of a Simultaneous Model of Auto Ownership and Mode Choice to Work. Some of the deficiences of the conventional urban transport modelling system are reviewed and a case is made for the use of simultaneous models estimated with disaggregate data.     

Characterization and evolution of spatial density patterns in urban areas

This paper examines the spatial patterns of population density, household automobile ownership and other socio-demographic variables that affect urban travel, as a function of distance from the central city core. Spatial density functions provide a useful characterization of urban structure, and of its evolution when taken at different time intervals. Analysis of the data from four case cities (Austin, Atlanta, Dallas, Phoenix) for 1960, 1970 and 1980 reveals continuing overall dispersion away from the traditional central core, accompanied by the densification of formerly low-density suburbs. This presents implications for high congestion levels in the densifying suburban communities, comparable to those typically associated with the CBD. In addition, the analysis has captured the continuing growth of average household automobile ownership and revealed a distinct spatial pattern that seems to be robust across the case areas considered, as well as within radial corridors in the one case that was so analyzed (Austin).List of symbols Y gross population density in census tractt - X _t distance in miles from the center of tract to the CBD - parameter representing the central business district density - y density gradient parameter - X₀, X₁, X2, and X3 locations of the knots in a three segment division of the x-axis - D_i dummy variable defined for thei-th segment - ₁ normally distributed disturbance term,a _i,b _i,c _i,d _i,i = 1, 2, 3 — parameters to be estimated - A _t area of census tractt     

An approach to the evaluation of changes in travel unreliability: A “Safety margin” hypothesis

Even where unreliability has been recognised as a significant component in the generalised cost of trip-making, few attempts have been made to quantify it in the evaluation of transport improvements. This neglect is perhaps explained by the difficulty of observing a suitable trade-off situation in which transport users can trade money directly or indirectly for improved reliability of their transport modes.This article investigates the characteristics of a possible trade-off which might be made by commuters — the allowance of extra time for travelling in order to avoid unpredictable lateness at destination. The form of the costs of a response to unreliability of this nature is considered within a more general framework of the allocation of time under uncertainty or risk conditions.Certain other approaches to the evaluation of travel unreliability are reviewed and a brief outline is given to a current research project which attempts to test the applicability of the safety margin in London commuters' timing of the trips that they take to work.Any views expressed in this article are those of the author and are not necessarily those of the Department of the Environment.     

New methods of controlling vehicle ownership and usage in Singapore

Over the years Singapore has introduced several fiscal measures aimed at restraining car ownership and usage and thus preventing traffic congestion. Two new methods have recently been added: the Vehicle Quota System which limits the number of new vehicles registered each month and the Weekend Car Scheme which allows cars to be registered for use during off-peak hours only, with substantial financial savings to the owners. The Vehicle Quota System involves monthly public tenders for Certificates of Entitlement needed to register new cars. Over the past 30 months the cost of COE's has been increasing and now constitutes between 12% and 27% of the on-the-road price of a new car. The fluctuations in the COE premiums for different vehicle categories are presented and analysed. The initial problems and the recent modifications made as a result of public pressure are also described. It seems that the increases in COE premiums are likely to continue under strong economic growth conditions as the demand for cars is more income-elastic than price-elastic.     

The benefits to the public of vehicle legislation — Attempts to measure the unmeasurable

Although inevitably there are grey areas, a distinction may be drawn between environmental disbenefits arising from vehicles which cause annoyance, such as noise, or loss of peace and quiet, vibration, visual intrusion, severance, and those which endanger life and limb. Legislation implemented to reduce either category will inevitably generate costs.It is suggested that in evaluating legislation relating to environmental nuisance, attempts should be made carefully to measure the benefits, while for legislation when life and limb is involved a cost-effectiveness approach should be adopted. Methods currently available to measure environmental nuisance arising from vehicles, for example opinion surveys, observing the effect of changes in some independent indicator, and simulation exercises are critically examined. Using evidence from the Urban Motorway Committee Reports, Noise Advisory Council, Transport and Road Research Laboratory surveys on the effect of traffic in selected High Streets, and the Realistic Environment Assessment Laboratory, Social and Community Planning Research ping-pong technique, studies of house price differentials, and estimates of willingness-to-pay for exclusion facilities, an attempt is made to highlight the dilemma that while benefits of environmental nuisance legislation should be carefully weighed against the anti-pollution costs, techniques currently available for measuring such benefits are very underdeveloped.Paradoxically there is a far more clear-cut procedure for valuing benefits of policies affecting life and limb. Official accident evaluation policy in the U.K. is described, and legislation affecting life and limb is examined.Finally, difficulties of effectively enforcing legislation of both environmental nuisance and life and limb categories are illustrated.     

Biases in response over time in a seven-day travel diary

Data from multi-day travel or activity diaries might be biased if recording inaccuracies and tendencies for respondents to skip certain types of trips or activities increases (or decreases) from day-to-day over the diary period. One objective of the research reported here is to test for such temporal biases in a seven-day travel diary. A second objective is to calculate correction factors which can be applied to the data in the case that biases are found. The analyses were conducted using regression and analysis-of-variance techniques. The variables investigated included total trips per day, total travel time per day, and trips per day by various modes (such as walking, car driver and car passenger). Results showed that most biases per capita statistics are due to increases over time in the percentage of respondents reporting no travel at all for an entire day. However, even after accounting for this bias by measuring statistics in terms of per mobile person, there remains a decrease over time of about 3.5 percent per day in the reporting of walking trips. This appears to be the main factor in the overall bias of about one percent per day in total trips per mobile person per day. No significant differences were found among population segments in terms of the levels of their biases.     

Allocation of funds to public transport investment and operating support

This paper reviews the present levels of operating support to, and public investment in, public transport systems in Western Europe. All internal bus, tram and rail services are included, and estimates made for total support in Britain, Sweden, West Germany, the Netherlands and France. To make comparison meaningful, these are shown in relation to GDP and traffic carried. Support levels in Britain are below average, but by no means the lowest as sometimes assumed. Reasons for providing support are considered, including existence of financial burdens arising historically, assistance to particular groups of users, problems in price discrimination and inability of other modes' charges to reflect costs. The extent to which support payments may merely subsidise inefficiency is outlined. A distinction is drawn between productive efficiency, i.e. the resources used to provide a specified level of service and fare, and allocative efficiency, i.e. the extent to which resources are allocated so as to maximise traffic, etc. The extent for reducing support yet retaining the present general level of service and fare is considered.Means of raising finance for support are outlined, including relative roles of central and local government. The scope of local taxes being raised to meet local objectives is considered, notably in the French versement transport: In conclusion, it is suggested that trunk inter-city services should cover all costs from fares, by a discriminatory pricing policy, but central government provide a basic support level for rural areas. In urban areas, practical limits exist to price discrimination, and the best policy may be collective purchase of facilities through a local tax.     

The Market for Transportation-Land Use Integration: Do Developers Want Smarter Growth than Regulations Allow?

Transportation and land use research of the past decade has focused in large part on the question of whether manipulating land uses in the direction of smart growth alternatives can reduce vehicle miles traveled (VMT) or otherwise improve travel behavior. Yet the notion of manipulating land uses implies that the alternative is somehow self-organized or market-based. This view appears to underestimate the extent to which current planning interventions in the United States – largely focused on lowering development densities, mandating ample road and parking designs, and separating land uses – impose an auto-oriented template on most new development. Rather than a market failure, the paucity of smart growth alternatives may be a planning failure – the result of municipal regulatory exclusion. This problem definition would shift the burden of proof for policy reform, as uncertainty in travel-behavior benefits would hardly justify the continuation of exclusionary regulations. If municipal regulations in fact constrain alternatives to low-density, auto-oriented development, one would expect developers to perceive unsatisfied market interest in such development. This article studies, through a national survey (676 respondents), US developers' perceptions of the market for pedestrian-and transit-oriented development forms. Overall, respondents perceive considerable market interest in alternative development forms, but believe that there is inadequate supply of such alternatives relative to market demand. Developer-respondents attribute this gap between supply and demand principally to local government regulation. When asked how the relaxation of these regulations would affect their product, majorities of developers indicated that such liberalization would lead them to develop in a denser and more mixed-use fashion, particularly in close-in suburban locales. Results are interpreted in favor land-policy reform based on the expansion of choice in transportation and land use. This view contrasts with a more prevalent approach which conditions policy interventions on scientific evidence of travel-behavior modification.     

The state-of-the-art of “comprehensive” planning

Planning occurs as a part of governmental operations wherever decision-making happens. For US metropolitan areas, the locuses of decision-making are multiple, ranging in scale from very small jurisdictions up through the hierarchy to state and federal levels, and in function from general governments to many special-purpose agencies — transportation, health care, education, etc. Almost all might affect or be affected by urban transportation decisions and actions. Since no one of these units of government is comprehensive in authority and activity, there is no single, centralized planning operation that is truly comprehensive. Pluralistic planning is increasingly trying to foresee and to accommodate the interactions among the various levels and functions. Instead of fragmenting, with the fragments pulled apart and insulated, we need to move toward partitioning, not merely to delimit boundaries but also to identify interfaces. This movement is hampered by the differentials in the development of the state-of-the-art of the technical planning process now used by the several levels and functional units of government. This is most advanced, and most effective, for small, homogeneous suburban jurisdictions primarily concerned with guiding and controlling physical development; it is in disarray in central cities trying to cope with social and economic problems as well as with physical deterioration; at the metropolitan scale it is highly developed technically but not very influential. There is a trend toward a network of planning activities that recognizes and facilitates interrelationships and interactions, both vertically among functional boundaries and horizontally across geographical-scale distinctions — a trend toward the comprehensive —but we have a very long way to go.Paper prepared for the Highway Research Board Conference on Organization for Continuing Urban Transportation Planning.     

Office location — city or suburbs?

Suburban offices constitute a growing proportion of the metropolitan office stock in Melbourne. The relocation of around 1700 Coles Myer employees from the Central Business District to Tooronga, 8.5 km south east from the GPO, is an example of office decentralisation. A study of the resultant impacts arising from the relocation has been conducted utilising a before-the-move and after-the-move survey of Coles Myer employees. Both surveys generated response rates in excess of 60%. Office relocation can have various short and long term impacts on employees and will influence decisions relating to residential location, car ownership and the resultant travel and activity patterns. It is not until these impacts are quantified that planners can gain acceptance for strategies designed to minimise the negative impacts associated with dispersed employment opportunities.This paper discuses the suburbanisation of office employment in Melbourne and studies the travel related effect on the employees, whose headoffice is relocated from the CAD to a suburban location. One of the great challenges for transport in the 90's will be the successful management of office location and the resultant impacts on travel.Abbreviations CAD Central Activities District; the CAD is defined as a slightly larger area than that previously referred to as the Central Business District (CBD)     

Gateway diversity and competition in international air transportation

Because of the existence of limited designation gateways, i.e., gateways for international air travel where entry by U.S. flag carriers is limited (in many cases to only one carrier), the U.S. Civil Aeronautics Board (CAB) has announced a policy of gateway competition. This policy seeks to maximize inter-gateway competition as a goal of the carrier selection process. The paper reviews the rationale and history of this policy and the economic principles of gateway competition. After addressing exceptions where gateway competition does not enhance competitive goals, the issue of how to enforce the credibility of the bidding process in route awards is addressed. The paper concludes by identifying circumstances where competitive objectives are not advanced through application of the principle gateway competition.     

The opening of the Amsterdam Ring Road

This paper presents the results of a major before-and-after study carried out to establish the short term effects of the removal of a severe bottleneck in the road network around Amsterdam. An important focus in the study was on measuring changes in the timing of travel, as well as changes in route choice, mode choice, destination choice and frequency of travel. The results of the study indicated that, in the short run, there was little or no change in mode choice, nor was there significant emergence of new induced trips. On the other hand, large shifts in time of travel as well as route choice were reported, emphasising the importance of alterations to the timing and routes of existing trips when congestion is relieved, and the need to consider the benefits these bring in evaluating the impact of any road investment.     

Modelling car availability,modal split and trip distribution by Monte-Carlo simulation: A short way to integrated models

The model used a Monte-Carlo algorithm to simulate modal split and trip distribution as an interconnected decision process at the individual level. Using census data, the individuals of a planning region are classified into situation groups, which represent significantly different decision situations with respect to socio-demographic position and territorial location. According to the theoretical framework, which emphasises mobility constraints instead of preferences, household structure and sex (time budget and car availability constraints) and work place characteristics (location constraints) are the key variables. For each situation group, decision profiles are empirically determined; these describe car availability, travel time constraints and work place distribution. Modal split and trip distribution are simulated as an interconnected individual decision process, which is stochastically determined by the location of the individual and the decision profile of his situation group.The algorithm is very sensitive and flexible and extremely well suited to electronic processing. An extended and modified version is currently being used in the preparation of regional transporation plans for several German city regions.     

What is induced traffic?

Investment in new or up-graded roads both raises the level and alters the pattern of accessibility over the whole area served by the road system. Vehicle-users will perceive the opportunities that this increased accessibility offers and respond in various ways, most of which can lead to more rather than less travel on the system. To the extent that travel increases overall, it can be said to have been induced by the road-improvement. Conversely, congestion as it spreads on the network will deter some travel and can be said to have a traffic suppression effect.The purpose of this first paper is to spell out, as clearly as possible, what is meant by induced traffic and to relate its various components to the full range of behavioural responses by travellers. In doing so, it draws upon the recently published (December 1994) report by the Standing Advisory Committee on Trunk Road Assessment (SACTRA) and response by the UK Government. The paper concludes with some of the implications of induced/suppressed traffic for current methods of forecasting and evaluation of road investment, which are covered in more detail by subsequent authors.     

Travel demand model system for the information era

The emergence of new information technologies and recent advances in existing technologies have provided new dimensions for travel demand decisions. In this paper we propose a comprehensive travel demand modeling framework to identify and model the urban development decisions of firms and developers and the mobility, activity and travel decisions of individuals and households, and to develop a system of models that can be used by decision makers and planners to evaluate the effects of changes in the transportation system and development of information technologies (e.g. various tele-commuting, tele-services and Intelligent Transportation Systems).The implementation of an operational model system based on this framework is envisioned as an incremental process starting with the current best practice of disaggregate travel demand model systems. To this end, we present an activity-based model system as the first stage in the development of an operational model system.     

Indicators of urban accessibility: Theory and application

The concept of accessibility and its related indicators have been in use for a long time, with still diverging interpretations of their significance and formulation. In this paper, a review is made of various existing theoretical bases, with special emphasis on recent behavioural approaches. It is suggested that this theoretical framework now allows a better appraisal of accessibility indicators and precise recommendations are proposed for their practical formulation and use. Various examples are given, especially for disaggregate analysis where a calculation for a given person is proposed instead of the conventional calculation .by a given mode. Finally, the relations between accessibility and trip rate are examined; from a study made in French cities, it is suggested that accessibility is a powerful determinant of trip rate.     

An evaluation of activity-based travel analysis

This paper is a review and assessment of the contributions made by activity-based approaches to the understanding and forecasting of travel behavior. In their brief history of approximately a decade, activity-based analyses have received extensive interest. This work has led to an accumulation of empirical evidence and new insights and has made substantial contributions toward the better understanding of travel behavior. However, practical applications of the approach in transportation planning and policy development have been scarce. Based on an analysis of the inherent characteristics of the activity-based approach, a review of recent (after the 1981 Oxford conference) developments, and a synthesis of the findings from past empirical studies, this study attempts to evaluate the contribution made by activity-based analyses and determine the reasons for the limited practical application. Recommendations are made for the future development of activity-based analysis as a science of travel behavior and as a tool in the practice of transportation planning and policy development.