The safety impact of the 65 mph speed limit: a case study using Alabama accident records. Final grant report.

National Highway Traffic Safety Administration, Office of Research and Development, Washington, D.C.

Industrial accident records : their compilation and use.

B̋ooklet No. 3."

Estimation and prediction of average vehicle occupancies using traffic accident records

As congestion management strategies begin to put more emphasis on person trips than vehicle trips, the need for vehicle occupancy data has become more critical. The traditional methods of collecting these data include the roadside windshield method and the carousel method. These methods are labor-intensive and expensive. An alternative to these traditional methods is to make use of the vehicle occupancy information in traffic accident records. This method is cost effective and may provide better spatial and temporal coverage than the traditional methods. However, this method is subject to potential biases resulting from under- and over-involvement of certain population sectors and certain types of accidents in traffic accident records. In this dissertation, three such potential biases, i.e., accident severity, driver’s age, and driver’s gender, were investigated and the corresponding bias factors were developed as needed. The results show that although multi-occupant vehicles are involved in higher percentages of severe accidents than are single-occupant vehicles, multi-occupant vehicles in the whole accident vehicle population were not overrepresented in the accident database. On the other hand, a significant difference was found between the distributions of the ages and genders of drivers involved in accidents and those of the general driving population. An information system that incorporates adjustments for the potential biases was developed to estimate the average vehicle occupancies (AVOs) for different types of roadways on the Florida state roadway system. A reasonableness check of the results from the system shows AVO estimates that are highly consistent with expectations. In addition, comparisons of AVOs from accident data with the field estimates show that the two data sources produce relatively consistent results. While accident records can be used to obtain the historical AVO trends and field data can be used to estimate the current AVOs, no known methods have been developed to project future AVOs. Four regression models for the purpose of predicting weekday AVOs on different levels of geographic areas and roadway types were developed as part of this dissertation. The models show that such socioeconomic factors as income, vehicle ownership, and employment have a significant impact on AVOs.

Estimation and Prediction of Average Vehicle Occupancies using Traffic Accident Records

As congestion management strategies begin to put more emphasis on person trips than vehicle trips, the need for vehicle occupancy data has become more critical. The traditional methods of collecting these data include the roadside windshield method and the carousel method. These methods are labor-intensive and expensive. An alternative to these traditional methods is to make use of the vehicle occupancy information in traffic accident records. This method is cost effective and may provide better spatial and temporal coverage than the traditional methods. However, this method is subject to potential biases resulting from under- and over-involvement of certain population sectors and certain types of accidents in traffic accident records. In this dissertation, three such potential biases, i.e., accident severity, driver¡¯s age, and driver¡¯s gender, were investigated and the corresponding bias factors were developed as needed. The results show that although multi-occupant vehicles are involved in higher percentages of severe accidents than are single-occupant vehicles, multi-occupant vehicles in the whole accident vehicle population were not overrepresented in the accident database. On the other hand, a significant difference was found between the distributions of the ages and genders of drivers involved in accidents and those of the general driving population. An information system that incorporates adjustments for the potential biases was developed to estimate the average vehicle occupancies (AVOs) for different types of roadways on the Florida state roadway system. A reasonableness check of the results from the system shows AVO estimates that are highly consistent with expectations. In addition, comparisons of AVOs from accident data with the field estimates show that the two data sources produce relatively consistent results. While accident records can be used to obtain the historical AVO trends and field data can be used to estimate the current AVOs, no known methods have been developed to project future AVOs. Four regression models for the purpose of predicting weekday AVOs on different levels of geographic areas and roadway types were developed as part of this dissertation. The models show that such socioeconomic factors as income, vehicle ownership, and employment have a significant impact on AVOs.

Data coding system for highway accident reports. Final report.

National Highway Safety Bureau, Washington, D.C.

Evaluation of BMCS accident files. Final report.

Federal Highway Administration, Washington, D.C.

Accident pathology, registry and training; in depth investigation of motor vehicle fatalities. Final report.

National Highway Safety Bureau, Washington, D.C.

Statistical summary of school bus accident data. Volume I of I. Final report.

National Highway Safety Bureau, Washington, D.C.

Determination of the operational performance requirements for a roadside accident countermeasure warrant system. Volume II - technical documentation. Final report.

Federal Highway Administration, Office of Safety and Traffic Operations Research and Development, McLean, Va.

Accident analysis for urban freeways. Volume I. Technical report. Final report.

Texas State Department of Highways and Public Transportation, Transportation Planning Division, Austin

Accident analysis for urban freeways. Volume II. MAAP user manual. Final report.

Texas State Department of Highways and Public Transportation, Transportation Planning Division, Austin

The National Accident Sampling System - a status report. Volume I: objectives of the National Accident Sampling System.

Mode of access: Internet.

The National Accident Sampling System - a status report. Volume III: implementation of NASS subsystems.

Mode of access: Internet.

The use and analysis of recorded traffic accident data. Final report.

Texas State Department of Highways and Public Transportation, Transportation Planning Division, Austin

The National Accident Sampling System - a status report. Volume IV: implementation schedule and resource requirements.

Mode of access: Internet.