This paper reports on the first phase of the location technology evaluation for probe vehicles. Two technologies were evaluated, Global Positioning Systems (GPS) and the cellular phone tracking technology developed by US Wireless. Although GPS has shown great potential for vehicle probes, much of the previous research is theoretical in nature. Very little work has been done in the areas of experimental research, implementation or deployment. Most of the field tests were anecdotal; a systematic approach is highly desired to develop a vehicle probe system that is reliable and efficient for traffic management. If GPS is widely deployed in cellular phones, as GTE in 1998 predicted would happen, GPS technology will become even more attractive and realistic for vehicle probe activities. A custom software package was developed as part of this project in order to conduct the technology evaluation. The software, the Travel Information Probe System (TIPS) maps positions of probes of arbitrary accuracy to an embedded Geographical Information System (GIS) in order to determine the path the probe took. Once the path has been determined, the software calculates the travel time for each road segment traversed. The preliminary analysis of two Bay Area counties showed that accurate location technologies are capable of producing travel time information for nearly all roads. A technology with 20-meter accuracy can produce data for 99.2% of road segments and 98.9% of the freeway segments in the two counties studied.

Providing easy access to the public transit service is the goal of the California transit agencies. Many travelers cannot take an express transit because they often cannot park and ride. Smart DRT (demand responsive transit) Feeder is a system that collects transit riders from neighborhoods and takes them to transit stations. This system will use APTS (Advanced Public Transit System) technologies to make the feeder service convenient and reliable. The concept is very simple. When demand is high, Smart Feeder will use the fixed-route fixedschedule service. When demand is low, it will use the on-demand service. For the on-demand service, customers will use an automated dial-a-ride system or the Internet for making a reservation or receiving a confirmation. Feeder vehicles will be equipped with Automated Vehicle Location (AVL) and on-board wireless computer devices. The first part of this paper describes the results of a user survey on the demand for and on the desired characteristics of a Smart Feeder system for the city of Millbrae. The second part of the paper describes the resulting design and implementation of the automated dial-a-ride system that will be used for the demand responsive transit service. The system uses an automated phone-in system for reservations, computerized dispatching over a wireless communication channel to the bus driver, and an automated callback system for customer notifications. User requests for pickup are collected and a computerized scheduling system acts as a broker between the multiple user requests and the transit agency to determine the optimal departure time and route that minimizes customer wait time and maximizes the number of passengers per trip. The system requires no dispatchers and operates in real time without requiring advance reservations.