Article Abstracts
Volume 2, No. 4, 1999Planning and Analyzing Transit Networks: An Integrated Approach Regarding Requirements of Passengers and Operators
Markus Friedrich, Transport Planning Systems Unit, PTV
Thomas Haupt, Transportation Modeling Unit, PTV
Klaus Noekel, Research and Development Unit, PTVAbstract
Providing an equally sufficient and efficient transit service requires careful planning and permanent monitoring of service quality, operating costs, and revenues. These requirements need a model that is capable of determining impacts on passengers as well as operators. Additionally, it is important to provide suitable and powerful methods to design and to modify the transit network. The transport planning software VISUM attempts to fulfill these requirements. In contrast to conventional Geographic Information Systems (GIS), which are extended to provide specific functionality for transit planning, VISUM is a comprehensive transportation model with additional GIS functionality. It seeks to fill the gap between conventional GIS programs and vehicle scheduling programs.
Transit GIS Applications in Fairfax County, Virginia
Wenyu Jia and Brendan Ford
Fairfax County Geographic Information ServicesAbstract
The Fairfax County Department of Transportation (DOT) manages a fixed-route bus system (the Fairfax Connector) that encompasses 58 routes. To better support the planning, operation, and marketing of this bus system, the Fairfax County DOT and the Fairfax County Department of Information Technology formed a team to develop a pilot project of Geographic Information Systems (GIS) transit applications. These applications would serve as a demonstration to facilitate automation, analysis, accessing, and plotting of transit data. To be successful, the applications had to be cost effective and match users’ technical needs with their abilities. Paramount to the success of this project was having a transit database capable of supporting all the applications identified by the development team. The database had to handle problems such as bus stops serving more than one route and routing varying by time of day. To effectively model the bus routes in GIS, each path had to be uniquely identified even though the same route could travel on different paths. Dynamic segmentation of ARC/INFO v.7.1 was used to develop the route database. A bus stop database, in the format of ARC/INFO coverage, was then related to the route coverage. More than 15 applications were identified for three areas of transit management: planning, operation, and marketing. Planning applications focused on transit service improvement and route restructuring. They included routing adjustment, route demographic and land-use analysis, and reporting of statistics required by the National Transit Database. Operation applications were designed for daily service monitoring and consisted of route running times, loading at bus stops, and emergency service. Marketing applications emphasized functions for public outreach, which included creating specialized route and stop maps and publishing route information on the Internet. Most end-user applications were built in ArcView 3.0 using Avenue and Dialog Designer. Some applications were built with ESRI’s Map Objects (MO) and Map Objects Internet Map Server.
Evaluating Transit Market Potential and Selecting Locations of Transit Service Facilities Using GIS
Srinivas S. Pulugurtha and Shashi S. Nambisan,
UNLV Transportation Research Center
Nanda Srinivasan, Cambridge Systematics Inc.Abstract
Accessibility to transit service facility (TSF) locations plays a significant role in the success of public transportation systems. The ease with which the end-user can reach a TSF (e.g., bus stops, rail stations, or multimodal centers) plays prominently in the decision-making process of the individual. This article presents a working definition for transit market potential based on accessibility in terms of walking distance and walking time. Further, a measure is constructed to evaluate transit market potential for TSF locations for a transit system. The measure of transit potential is represented by an index value based on demographic criteria such as employment, household size, vehicle ownership, etc. This index can be used to identify locations of TSFs that increase a route’s potential for ridership. A methodology is proposed to estimate the Index of Transit Potential for TSFs. This methodology involves (1) identifying the accessible network of streets around each TSF that is within an acceptable access threshold for a transit rider, and (2) estimating the transit market potential based on key demographic characteristics. The analytical and visualization capabilities of a Geographic Information Systems (GIS) program are utilized to help attain the objective. A case study is used to demonstrate the application of the methodology. In the case study, a portion of a route of the Las Vegas Citizens Area Transit (CAT) system is analyzed and the Index of Transit Potential is estimated. The index values are then used to locate TSFs along the route. This is compared with the existing stop locations for the route.
A Transit Access Analysis of TANF Recipients in Portland, Oregon
Thomas W. Sanchez, Portland State University
Abstract
Little evidence exists regarding the relationship between transit service availability and the ability of welfare recipients to find stable employment. While policy-makers continue to assert that increased public transit mobility can positively affect employment status, there is little empirical evidence to support this theory. It is generally assumed that public transit can effectively link unemployed, carless persons with appropriate job locations. From these assumptions stems the common belief that if adequate transit were available, the likelihood of being employed would increase. Hence, the call for more transit services to assist moving welfare recipients to gainful employment. Current available evidence is anecdotal, while general patterns of transit access and labor participation remain relatively unexplored. This analysis examines whether transit access service is less available to Temporary Assistance for Needy Families (TANF) recipients in the City of Portland, Oregon. It uses disaggregate TANF recipient location data from the State of Oregon Department of Adult and Family Services (AFS); transit route/stop data from Tri-Met; block-group census data; and disaggregate employment location data within Geographic Information Systems (GIS). GIS capabilities are essential in performing network accessibility analyses and for analyzing spatial patterns of TANF recipient and employment locations. The results of this analysis provide an assessment of the availability and quality of transit service for TANF recipients.
GIS-Based Support System for On-Demand Flexroute Transit Service
Brian L. Smith, University of Virginia
Priya K. Durvasula, ALK Associates, Inc.
Stephen C. Brich, Virginia Transportation Research CouncilAbstract
Geographic Information Systems (GIS) are a proven resource for public transportation service planning and evaluation. In particular, their spatial analysis and database management capabilities make them well suited for such applications. The primary cost incurred in a GIS application is for the development and maintenance of high-quality spatial databases. Due to this cost, public transportation agencies want to utilize these databases to support a wider array of applications. As desktop GIS software and computer hardware become more powerful, GIS can be used to develop applications for “real-time” operations. In this research effort, a GIS-based prototype system was developed and tested to support the scheduling and dispatch functions of an on-demand flexroute transit service. The effectiveness of the prototype demonstrates the potential of GIS to support time-critical transit operations.