TravInfo Evaluation (Technology Element) Traveler Information Center (TIC) Study: System Reliability and Communications Interface (9/96-12/97)

Problem

TravInfo is a field operational test (FOT) of advanced traveler information systems (ATIS) for the San Francisco Bay Area. The project seeks to compile, integrate, and broadly distribute timely and accurate multi-modal traveler information through commercial products and services. The public sector component centers on the Traveler Information Center (TIC), which collects and integrates both static and dynamic traveler information.

This study focused on the technology component of the TravInfo project. The technology evaluation covered in this paper consists of four elements: systems reliability, communications interface, operator interface, and response time analysis. This study focused particularly on system reliability and the communications interface during the period July through December 1997. Study results from the period September 1996 to June 1997 are reported in UCB-ITS-PWP-98-7.

The communications interface is divided into two distinct groups: Traveler Advisory Telephone System (TATS), utilized primarily by the traveling public to access traffic and transit information, and LDS (Landline Data System), utilized primarily by the private sector to download traffic information to add value to it and re-sell to the public.

Findings

During the period between July and December 1997, 38 new or non-recurring internal problems were experienced at the TIC. These problems were quite different than those experienced during the period September 1996 to June 1997. These problems were classified as critical, major, and minor with a frequency of occurrence of 39.5, 44.7, and 15.8 percent, respectively.

With the exception of the month of September 1997 during which the Bay Area Rapid Transit (BART) system workers were on strike causing an initial surge in call volume, the volume of TATS has remained fairly constant (50,000 to 60,000 calls per month). Call volume was at about 3 percent of the TATS system capacity except during the first two days of the BART strike when it rose to as high as 75 percent during peak hours.

LDS usage was fairly limited and well below capacity during the period of study. Access by the private sector participants is essentially limited to three providers, one of which accounts for approximately 90 percent of the total data accessed. The TravInfo system has not yet stimulated development of publicly available ATIS products. Troubling for TravInfo is the fact that between 55 and 85 percent of the data accessed is speed and congestion data, which relies on loop detector data, 75 percent of which have critical accuracy problems.

Usage of TravInfo has fallen well short of that envisioned in the general goals set out for the TravInfo Field Operational Test. Collection of data has been satisfactory, with the exception of serious problems in loop detector data quality. However, dissemination of the data, as reflected in TATS usage, fell far short of the study's goal.