This document is a reference manual for the fsp and xfsp programs. The fsp program is a software tool used to interrogate the data that was collected during the Freeway Service Patrol Evaluation Project. The purpose of the program is to perform diagnostics on the data, generate error reports, and make plots of various pieces of data. The xfsp program is a graphical user interface to the fsp program. It allows the user to create the runfile and the incident filter that the fsp proram requires by pointing and clicking on various butons and widgets with the mouse.

This paper presents a methodology to evaluate a benefit-to-cost ratio effectiveness of the Freeway Service Patrol in a freeway section in Los Angeles. The methodology addresses the process of estimating incident delay using probe vehicles and the lack of "before" data.

The paper describes a methodology and its application to measure total, recurrent, and non-recurrent (incident related) delay on urban freeways. The methodology uses data from loop detectors and calculates the average and the probability distribution of delays. Application of the methodology to two real-life freeway corridors—one in Los Angeles and the other in the Bay Area—indicates that reliable measurement of congestion should also provide measures of uncertainty in congestion. In the two applications, incident-related delay is found to be between 13 to 30 percent of the total congestion delay during peak periods. The methodology also quantifies the congestion impacts on travel time and travel time variability.

The paper describes a methodology and its application to measure total, recurrent, and non-recurrent (incident related) delay on urban freeways. The methodology uses data from loop detectors and calculates the average and the probability distribution of delays. Application of the methodology to two real-life freeway corridors—one in Los Angeles and the other in the Bay Area—indicates that reliable measurement of congestion should also provide measures of uncertainty in congestion. In the two applications, incident-related delay is found to be between 13 to 30 percent of the total congestion delay during peak periods. The methodology also quantifies the congestion impacts on travel time and travel time variability.

The highway congestion monitoring program (HICOMP) report is based on data from tach vehicle runs or PeMS. Research under TO 5319 compares the accuracy and cost of these two alternatives. The detailed studies described in the report lead to the following conclusions and suggestions for follow-on work:

1. In freeway sections with good quality detectors spaced at most one-half mile apart, PeMS-based estimates of the magnitude, extent and duration of congestion are incomparably more accurate than those based on tach vehicle runs.

2. Because at most four days of tach run data are used to estimate the annual congestion over a freeway segment, the error in these estimates is on the order of 25 percent. (With only one day of tach runs, which is typical, the error is 50 percent.) The error in year to year comparisons is on the order of 35 percent, and so one can have no confidence in such comparisons published in the HICOMP report.

3. Because the location and number of detectors within a district varies significantly from year to year and the quality of the loop detector data is uneven, it is hazardous to use PeMS-based congestion estimates to make inter-district or year to year comparisons. However, careful analyses using PeMS data can yield valid comparisons.

4. PeMS data collection costs a fraction of tach-vehicle runs that yield estimates with similar accuracy. It would be more beneficial to divert resources from tach runs into improving the detection system.

5. PeMS estimates the components of recurrent and non-recurrent congestion; congestion ‘hotspots’; and travel time reliability. Inclusion of these estimates will make HICOMP reports much more useful.

6. An outline of a standardized congestion reporting protocol is offered. It takes into account the errors introduced from too few tach runs, loop detectors with large spacing or poor quality. It suggests a transition plan to move towards a PeMS-based report.

This report presents the results of a study designed to evaluate the effectiveness of the freeway service patrols (FSP) on a section of I-10 in Los Angeles. An evaluation methodology was used to estimate incident delays based on loop detector data and probe vehicles, and derive estimates of savings in performance measures in the absence of data for before FSP conditions. The estimated benefit cost ratios based on delay and fuel savings for a range of typical reductions in incident durations indicate that FSP produces significant benefits at the test site. Additional benefits include reductions in air pollutant emissions, secondary accidents, highway patrol time used on non-enforcement activities, increased safety to assisted motorists, and more efficient operation of the freeway system.

The Los Angeles Freeway Service Patrol (FSP) Evaluation project is measuring the effectiveness of the FSP program on a specific freeway site in Los Angeles. This report describes the site selection and database development phases of the project. From an initial list of ten possible sites, detailed analysis was performed in order to rank the sites according to specific parameters developed by the study team. Site selection was based on congestion levels, average travel speeds, shoulder width, number of in-lane FSP assists, average daily traffic, directionality and the density of functional loop detectors. The site selected was FSP Beat 8, which is located on Interstate Route 10, between Eastern Avenue and Santa Anita Avenue.

Once the site was selected, a detailed, comprehensive, computerized database was developed. This database completely describes the traffic conditions along Beat 8 for 32 weekdays, for a total of six hours each day. This 192-hour database includes detailed descriptions for 1,560 incidents, tach vehicle travel time traces for 3,619 runs (at 5.7 minute headways), and loop detector data (30-second flow and occupancy) from 240 loop detectors. Finally, the CHP has provided electronic CAD logs for the entire study period. Further to the documentation included in this report, preliminary incident analysis is included in PATH Working Paper 97-18 and the methodology and preliminary evaluation results are included in PATH Working Paper 97-17.

We present a novel, off-line approach for evaluating incident detection algorithms. Previous evaluations have focused on determining the detection rate versus false alarm rate curve -- a process which we argue is inherently fraught with difficulties. Instead, we propose a cost-benefit analysis where cost mimics the real costs of implementing the algorithm and benefit is in terms of reduction in congestion. We argue that these quantities are of more practical interest than the traditional rates. Moreover, these costs, estimated on training data, can be used both as a mechanism to fine-tune a single algorithm as well as a meaningful quantity for direct comparisons between different types of incident detection algorithms. We demonstrate our approach with a detailed example. Key words: Incident detection

his report presents the findings of a comprehensive evaluation of the freeway service patrol (FSP) program on specific freeway section in the San Francisco Bay Area. The study methodology consisted of determining the savings in incident delay and other performance measures "before" and " after" the implementation of FSP based on field data and improved analysis procedures. Data were collected during the peak periods on a mile section of the I-880 freeway in the City of Hayward, Alameda County. Software was developed to process the field data and create a computerized database. Benefits of the FSP are discussed, along with suggestions for accurately assessing the effectiveness of incident management programs.