Article Abstracts

Volume 3, No. 4, 2001

Walk-and-Ride:
Factors Influencing Pedestrian Access to Transit
Robert Cervero
Univerity of Califoria, Berkeley

Abstract

The predominant means of reaching suburban rail stations in the United States is by private car. Transit villages strive, among other things, to convert larger shares of rail access trips to walk-and-ride, bike-and-ride, and bus-and-ride. Empirical evidence on how built environments influence walk-access to rail transit remains sketchy. In this article, analyses are carried out at two resolutions to address this question. Aggregate data from the San Francisco Bay Area reveal compact, mixed-use settings with minimal obstructions are conducive to walk-and-ride rail patronage. A disaggregate-level analysis of access trips to Washington Metrorail services by residents of Montgomery County, Maryland, shows that urban design, and particularly sidewalk provisions and street dimensions, significantly influence whether someone reaches a rail stop by foot or not. Elasticities are presented that summarize findings. The article concludes that conversion of park-and-ride lots to transit-oriented developments holds considerable promise for promoting walk-and-ride transit usage in years to come.

 

Visualization of Transit Mobility and Performance
Aníbal A. Galíndez, Los Angeles County
Metropolitan Transportation Authority
Ricardo Mireles-Córdova, Los Angeles Unified School District

Abstract

The visualization of a transit mobility model is presented in this article. The method described shows transit system capacity and utilization by area and time of day using ride-check data as a proxy for real-time information. It indicates how public transportation resources can be used in a more efficient and effective manner.

The visualization process requires the creation of a time/location data matrix of the variable to be analyzed and the linking of the performance measure to spatial data. This creates a temporal Geographic Information System (GIS) platform for the entire transit system or systems at the regional level. The GIS is "animated" to show snapshots of the system in sequence for the entire day. It serves as a powerful tool to evaluate bus route performance.

The visual display of transit system utilization facilitates the assessment of where, when, and what type of resources should be allocated to maximize transit utilization at the lowest possible cost. It also can serve as a graphical tool to inform the public and policy-makers about transit system performance. Different demand markets for transit (rail, bus fixed-route, shuttles, community circulators, vanpools, etc.) can be appraised and the effectiveness of current transit in serving these markets can be visualized. The method can be used to show where service can be allocated, thus enhancing the mobility of transit systems.

 

Multicriteria Feasibility Evaluation for Rural Transit in Georgia
George D. Mazur, Cambridge Systematics, Inc.
Karen K. Dixon, Georgia Institute of Technology
Wayne A. Sarasua, Clemson University

Abstract

This article describes transit feasibility analysis features of the Georgia Department of Transportation’s (GDOT’s) Multimodal Transportation Planning Tool (MTPT). Using open databases that are available agencywide, the MTPT can provide a system-level analysis of transportation requirements of rural areas, identify potential implementation constraints early in the planning process, and develop a prioritized project list by mode for an analysis region. In addition to demand-responsive transit, the MTPT addresses intercity bus, intercity passenger rail, commuter rail, highways, aviation, and bicycle modes. This article focuses on the demand-responsive transit component of the MTPT, and provides an overview of how the MTPT can help automate system-level transit planning for the general public in rural Georgia.

The MTPT transit analysis assesses service feasibility for nonurbanized areas that do not currently have local transit service for the general public. In the MTPT, transit service feasibility considers the existence of human service transit providers in the county; the percentage of population in certain “target” populations; and estimates of potential ridership, vehicle requirements, capital costs, operating costs, and economic benefits. The first factor indicates if opportunities may exist to coordinate service with existing providers, and helps to address funding issues. The second factor assesses market characteristics of the target area as one determinant of potential service need. The third factor provides a range of potential values for key operating and financial statistics at a system-planning level of analysis. The intent of the analysis is to identify those locations where it makes sense to more seriously analyze new demand-responsive services.

This article should be helpful for transportation planners with responsibility for developing system-level transportation plans and programs at the county, region, and state levels. It will also be helpful for decision-makers who are trying to match transit funding to areas with high service needs.

  

Evaluation of Garden State Parkway
Alternate Bus Routing
Field Operational Test
Kaan Ozbay, Tilanka Karunaratne, and Trefor Williams
Department of Civil and Environmental Engineering, Rutgers University
Diogenes Feldhaus and Mohsen Jafari
Department of Industrial Engineering, Rutgers University

Abstract

This study evaluates the effectiveness of the New Jersey Garden State Parkway (GSP) Alternate Bus Routing (ABR) system, an Advanced Public Transportation System (APTS). The GSP ABR Field Operational Test (FOT), which was conducted on a small portion of the parkway, was mainly concerned with real-time routing of New Jersey Transit (NJT) buses traveling the GSP to a parallel alternate route to avoid congestion on the parkway.

One of the most important features of this FOT is the use of NJT buses as probe vehicles that provide real-time travel-time information to the bus routing algorithm. The use of probe vehicles for network surveillance increases the attractiveness of similar systems that can be deployed over larger networks where infrastructure-based surveillance can be prohibitively expensive. The functional evaluation of GSP ABR includes the collection and analysis of data from various sources including traffic sensors, probe vehicles, and surveys conducted among transit bus operators and system users.

During the official testing period in 1997, the GSP ABR system produced accurate diversion messages, which proved the reliability of the system. However, the relatively short length of the alternate route, U.S. Route 9, and similar traffic patterns observed on both routes did not give the evaluation team the opportunity to observe scenarios where statistically significant travel-time improvements exist. This result prevented the evaluation team from reaching conclusive recommendations in terms of the effectiveness of this FOT. However, the survey results show that both transit bus operators and ABR system operators believe the system can be very beneficial if implemented in a different network.

From a policy point of view, the general conclusions of the functional tests presented along with a list of lessons learned can be used in the effective design of future FOTs in the area of APTS.

 

 

The Absence Consequences of Overtime in the Transit Industry
Yoram Shiftan, Technion, Israel Institute of Technology
Nigel H. M. Wilson, Massachusetts Institute of Technology

Abstract

The transit industry relies on overtime to fill in for worker absence or to cover unexpected extra work. The purpose of this article is to study the absence consequences of overtime in the transit industry through a disaggregate model of absence. The model was estimated with panel data of transit operators to test the hypothesis that widespread availability of overtime may induce absence. This might occur for two reasons. Some employees may be more likely to be absent after reaching a threshold pay amount for a period, and this level will be reached after fewer hours on the job if overtime work is readily available. Other employees may be absent more because of the increased stress and fatigue associated with regularly working long hours including overtime. The results suggest that absence is more a habit than the result of a decision process based on past overtime worked.