No abstract

Graphical scheduling is an old technique that has been neglected, or never acquired, in many NorthAmerican transit agencies. It retains its advantages in basic schedule design and analysis as it eases the solution to problems that Journal of Public Transportation IntroductionDevelopment and use of graphical schedules for planning and supervision of transit systems operations is by no means a new subject. It is a time-proven method used for both development and analysis of schedules. Yet, its use is far from universal. While many transit and railway systems use graphical schedules in their daily operations for multiple purposes, the entire concept and technique is virtually unknown in most North American transit systems, including the largest ones. The latest dispatching/control software packages in the United States that monitor buses in real-time through Automatic Vehicle Location (AVL) do not use it either. However, this software does display GIS maps showing vehicle location along streets, as well as checkpoint data in spreadsheet format.While the spreadsheet format is useful, the data display format that for many purposes reveals the most information-the time-distance diagram-should also be available. Actually, the graphical method is superior to the numerical ones for many applications. The purpose of this paper is to broaden the knowledge about this technique in those parts of the transportation community where it is not used and, often, where it is not even known.This paper is organized as follows. The following section describes the concept of the time-distance diagram and explains how it is designed and interpreted. The third describes several applications in scheduling and the advantages this technique provides. The fourth section describes its advantages in real-time operational control, an area of vital interest with the advent of highly capable Intelligent Transportation Systems (ITS) that provide precise vehicle locations and numerous communications options. The final section is a concluding summary.

Abstract. At the transition from a tangent section to a curved section, it is possible for a following vehicle with adaptive cruise control in car-following mode to lose track of the lead vehicle. This occurs because the lead vehicle enters the curve and its path diverges from the axis of the following vehicle, yet the following vehicle does not yet have lateral acceleration information that would induce its range sensor to bend according to the curvature of its own path. This is a temporary situation, but one that could have an impact on cruise control safety and appropriate algorithms. In this paper, the conditions of time and distance that produce this circumstance are derived. Examples are given using typical values of roadway and vehicle parameters. Finally, some conclusions regarding possible solutions are offered.

Since 2005, when "The Mobility Enhancement for the Mobility Impaired Act" was enacted, special transport systems(SPS) has been introduced by each responsible local entity. For its efficient operations and service enhancements, a clear understanding of travel patterns of SPS users is required. Yet we currently have a very limited understanding about them due to a lack of necessary data. This study represents an attempt to provide a better understanding of SPS user's travel patterns with the data generated by Gyeongsangnam-do SPS Call Center. The data include the number, time and day of calls, origins and destinations of callers, types of callers' impairement etc. The data thus allow one to analyze users' travel patterns, including area-wide O-D patterns. There were a number of interesting findings. For example, wheelchair users are only about 42% and the trips are made mostly on non-peak daytime periods. The results are expected to provide a helpful information not just for Center's SPS operations, but for other local entities that are interested in developing similar call centers as well. By refining the SPS system, periodic patterns of callers could be identified in the future.