Analysis of Metropolitan Highway Capacity and the growth in vehicle miles of travel

A number of recent studies have examined the hypothesis of induced travel in an attempt to quantify the phenomenon (Hansen & Huang 1997; Noland, forthcoming). No study has yet attempted to adjust for potential simultaneity bias in the results. This study addresses this issue by the use of an instrumental variable (two stage least squares) approach. Metropolitan level data compiled by the Texas Transportation Institute for their annual congestion report is used in the analysis and urbanized land area is used as an instrument for lane miles of capacity. While this is not an ideal instrument, results still suggest a strong causal relationship but probably that most previous work has had an upward bias in the coefficient estimates. The effect of lane mile additions on VMT growth is forecast and found to account for about 15% of annual VMT growth with substantial variation between metropolitan areas. This effect appears to be closely correlated with percent growth in lane miles, suggesting that rapidly growing areas can attribute a greater share of their VMT growth to growth in lane miles.     

Developing Transport Infrastructure in Sub-Saharan Africa through Public–Private Partnerships: Policy Practice and Implications

In contemporary times, Public–Private Partnership (PPP) in transport infrastructure has gained considerable attention in developing regions following its success in the developed countries. However, Sub-Saharan Africa (SSA) is among the developing regions with few transport PPP projects and among the regions with high number of failed projects. Meanwhile the region's transport infrastructure need far exceeds it current provision. This paper therefore aims to examine the project experiences (success and failure factors) of three highly profiled transport PPP projects, namely the Lekki toll road concession project (Nigeria), N4 toll road (South Africa/Mozambique) and Port of Maputo (Mozambique) in order to develop policy measures for effective future implementation. The experiences of the three projects show that transport PPP policy is indeed feasible in SSA. However, to realise its full applicability, proper policy actions and measures must be carefully observed and these include effective and efficient stakeholder management, transparent and competitive tendering process, high participation of local investors, stable macro-economic conditions and strong government commitment and regulatory framework. The projects experiences and policy actions developed are impactful in accelerating transport infrastructure development through PPP approach in SSA. Hence it is hoped that policy-makers and practitioners would be informed on the key strategies to employ in implementing future projects.     

Anatomy of a systems failure: Dial-a-ride in Santa Clara County,California

Late in 1974 and early in 1975 the Santa Clara County Transit District initiated, operated, and then discontinued a demand responsive dial-a-ride system within a -month span. This systems failure was primarily the result of poor systems planning. Specifically, four major mistakes were made that led to the death of the system. They were: (1) Inadequate Customer Communication System, (2) Starting the Entire System at Once, (3) Inadequate Number of Vehicles, and (4) Taxicab Buyout.Each of these four mistakes is discussed in detail. Recommendations for instituting dial-a-ride systems are made. Getting through the difficulties of the start-up period is emphasized. Costs are discussed, and some relevant cost data are presented.     

Problems of the carless in the United Kingdom and the United States

An examination of current population statistics shows that in the U.S. more than half of the population is without immediate access to a car, and in the U.K. more than three-fifths of the population is without access to a car. This phenomenon has been accentuated by national investment in both countries in major highway programs. The term carless refers to more than just households that own no cars. It extends, in households with cars to those without licenses (old and young), the handicapped, and even the licensed drivers who have no access to the family car when it is in use elsewhere (e.g. at work). The most severely effected are those in urban areas and especially the urban poor. Transportation expenses are limited for the poor when other family expenditures (food, shelter) take a high priority. Once the work trip has been satisfied, money for other trips, for the poor, is not always available. One solution to cost-free travel is pedestrianism (walking), but this too is difficult in urban areas where the pedestrian has been overlooked in favor of the car. Solutions to problems of the carless include dial-a-ride, better public transit, and better design of urban form.     

Second generation U.S. rail transit systems: Prospects and perils

So far in the decade of the 1970's, commitments have been made to construct a second generation of new rail systems in four urban areas — Atlanta, Baltimore, Miami and Buffalo. In this paper the authors speculate on the prospects and perils that lie ahead for these systems in the context of national and local expectations for rail transit and the experience of the first generation rail transit systems of San Francisco (BART) and Washington.     

Development of multimodal performance measures for transit systems in New York State

The New York State Department of Transportation was required to certify as to the economy and efficiency of transit operators participating in the State's public transportation operating assistance program. This paper describes the efforts undertaken to meet this mandate.Discussed are past efforts to link performance measures to funding programs; reasons for modifying measures which had been used in previous efforts; and some of the problems and issues raised by the use of such criteria. The paper identifies 15 performance measures being used by New York State in its evaluations, the actual ranges encountered in the transit operations being funded through the state program, and tentative acceptable and desirable levels of those measures which the Transportation Department is using in its evaluation. The role these measures play in the state's operating assistance policy decision process is also described.     

Role of the built environment on mode choice decisions: additional evidence on the impact of density

Density is a key component in the recent surge of mixed-use neighborhood developments. Empirical research has shown an inconsistent picture on the impact of density. In particular, it is unclear whether it is the density or the variables that go long with density that affect people’s travel behavior. Many existing studies on density neglect confounding factors, for example, residential self-selection, generalized travel cost, accessibility, and access to transit stations. In addition, most still use a single trip as their observation unit, even though trip chaining is well recognized. The goal of this paper is to assess the role of density in affecting mode choice decisions in home-based work tours, while controlling for confounding factors. Using the dataset collected in the New York Metropolitan Region, we estimated a simultaneous two-equation system comprising two mutually interacting dependent variables: car ownership and the propensity to use auto. The results confirm the role of density after controlling for the confounding factors; in particular, employment density at work exerts more influence than residential density at home. The study also demonstrates the importance of using tour as the analysis unit in mode choice decisions. The study advances the field by analyzing the role of the built environment on home-based work tours. New knowledge is obtained in the relative contribution of density vs. a set of correlated factors, including generalized travel cost, accessibility, and access to transit stations.

The effect of the London congestion charge on road casualties: an intervention analysis

The introduction of the congestion charge in central London on the 17th of February, 2003, led to a reduction in congestion. One factor that has not been fully analysed is the impact of the congestion charge on traffic casualties in London. Less car travel within the charging zone may result in fewer traffic collisions, however, as the number of pedestrians, cyclists, and motorcyclists increased after the introduction of the congestion charge, the number of traffic casualties associated with these groups may also have increased. Reductions in congestion can also lead to faster speeds. Therefore, there could be increases in injury severity for those crashes that do occur. An intervention analysis was conducted to investigate the effect of the congestion charge on traffic casualties for motorists, pedestrians, cyclists, and motorcyclists, both within the charging zone and in areas of London outside the zone. This was done for killed and serious injuries (known as KSI in British terminology) and for slight injuries to examine whether there were any shifts in severity outcomes. Our results suggest no statistically significant effect for total casualties in London, but within the charging zone there has been a statistically significant drop in motorist casualties, and possibly an increase in cyclist casualties. There is an associated effect of an increase in casualties of motorcyclists and cyclists in some areas outside the charging zone, suggesting that changes in the design of the congestion charge may be needed to achieve reductions in casualties.

Evaluation of the effect of cooperative infrastructure-to-vehicle systems on driver behavior

In-vehicle technologies and co-operative services have potential to ease congestion problems and improve traffic safety. This paper investigates the impact of infrastructure-to-vehicle co-operative systems, case of CO-OPerative SystEms for Intelligent Road Safety (COOPERS), on driver behavior. Thirty-five test drivers drove an instrumented vehicle, twice, with and without the system. Data related to driving behavior, physiological measurements, and user acceptance was collected. A macro-level approach was used to evaluate the potential impact of such systems on driver behavior and traffic safety. The results in terms of speeds, following gaps, and physiological measurements indicate a positive impact. Furthermore, drivers’ opinions show that the system is in general acceptable and useful.