Freeway service patrols have been cited as one of the most effective elements of an incident management program for reducing incident detection time and incident duration. Service patrol programs utilize roving vehicles to patrol congested and high incident sections of urban freeways. The state of the practice of freeway service patrol programs in the United States is documented in this paper. A telephone survey was conducted with managers of 53 freeway service patrols in 22 states. Approximately 74 percent of the surveyed service patrols are sponsored exclusively by public agencies. Approximately 47 percent of the surveyed patrols are sponsored exclusively by Department of Transportations; 6 percent are sponsored exclusively by police agencies; and 21 percent are sponsored by multiple public agencies. Approximately 34 percent of the patrols receive federal support funding. Finally, 27 percent of the patrols operate with private funding sources. Service patrol hours of operation vary from program to program, with the most common being coverage of the weekday a.m. and p.m. peak periods. Approximately 70 percent of the surveyed agencies own and operate their own vehicles, whereas 26 percent contract with private tow companies to provide drivers and vehicles. Benefits associated with service patrols are typically quantified by multiplying a value of time by the estimated delay reduction provided by the service patrol in vehicle-hours. Available benefit to cost analyses for 15 of the service patrols studied ranged from 2:1 to 36.2:1. A contact list and recommendations for agencies interested in starting a new service patrol program are also included in this paper.

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Link travel times are one of the most widely used and valuable measurements of congestion. Travel time measures are compatible with multimodal analyses and are understood by nontechnical audiences, yet are rigorous enough for technical analyses by transportation engineers and planners. The “average” car and floating car techniques are the most widely used travel time–based measures. Although there are cost, safety, and data limitation problems associated with collecting travel time data manually, the use of computer-aided travel time technology solves most of these problems. Detailed speed, time, and distance information can be safely collected in up to 0.1-sec intervals for a reasonable cost. The consistent format of the computer data lends itself to an automated analysis process. The development and benefits of using computer-aided travel time data collection techniques using distance-measuring instruments (DMI) and laptop computers are discussed. Automated analysis techniques and developmental software can produce results such as speed profiles, average speeds, level of service, and vehicle accelerations. Current and future research on air quality methods, fuel consumption information, and planning model potential is also presented.

An analysis of major freeway incidents in Houston, Texas, was conducted. The data base analyzed was provided by the Houston Police Department solo motorcycle patrol division. This division responds to all freeway lane-blocking incidents that are expected to last more than approximately 45 minutes. Over a 7-year period between 1986 and 1992, the division documented the details of 612 major freeway incidents to which it responded. From these data, it was estimated that major freeway incidents occur in Houston at a rate of 0.68 incident per 100 million vehicle-kilometers (MVK). That is equivalent to a major incident every 147 MVK. Major incidents were nearly 3.5 times as likely to occur within the interchanges (based on vehicle-kilometers driven) as between them. Of the 612 major incidents included in the data base, 498 (81.5 percent) involved trucks only (even though large truck traffic accounts for only 7.7 percent of the total vehicle-kilometers traveled on Houston freeways). Furthermore, lost or spilled loads and truck overturns account for nearly one-half of the major incidents in Houston. Information on incident severity and duration is also presented.