Computer Accident Typing for Bicyclist Accidents: Training Manual

NHTSA · 1983 · ROSA P / United States. Department of Transportation. National Highway Traffic Safety Administration

archive: archived pipeline: cataloged verified

Get this paper ↗ (full text — opens at the source; we link to it, we don't host it)

Summary

This document is a training manual published by the National Highway Traffic Safety Administration (NHTSA) in 1983, designed to instruct coders in the Computer Accident Typing (CAT) system for bicyclist-motor vehicle accidents. The primary objective is to standardize the classification of accident data to support traffic safety programs. The manual argues that accident typing is essential for defining local accident problems, developing targeted countermeasures, allocating community resources based on accident frequency, and evaluating the effectiveness of implemented safety measures. By converting accidents into specific types, communities can identify recurring patterns rather than treating accidents as random occurrences. The CAT system relies on a structured coding procedure where a human coder analyzes police accident reports and assigns numeric codes based on eight specific statements. These codes are then entered into a computer, which determines the final accident type from a set of 44 possible classifications. The manual outlines the use of a "Coder’s Handbook" and data recording forms. The coding process begins with an "Exceptions" statement, which handles specific scenarios such as intentional collisions, non-accidents, or incidents involving child’s vehicles or falling cargo. If no exception applies, the coder proceeds through seven additional statements: Motorist Primary Motion, Cyclist Primary Motion, Operator Actions, Accident Location, Initial Approach Paths, Motorist Error, and Cyclist Error. Each statement offers specific alternatives with corresponding codes, such as determining if a vehicle was backing, turning, or going forward, or if the accident occurred at a signalized intersection or midblock. The manual provides detailed definitions and visual aids to ensure consistent coding. For instance, it distinguishes between parallel and crossing approach paths and specifies how to determine right-of-way in crossing scenarios. It also details specific errors, such as "Swing Wide on Right Turn," "Cut Corner on Left Turn," or "Failed to Detect Cyclist." The text emphasizes avoiding "Unknown" codes when possible to prevent the computer from assigning an "Insufficient Information" type. The manual includes practice cases using real police reports to demonstrate the application of these rules, guiding the user through the step-by-step analysis of vehicle motions, locations, and operator errors to derive the correct numeric codes. The significance of this work lies in its contribution to systematic traffic safety analysis. By providing a rigorous, standardized method for categorizing bicycle accidents, the NHTSA enables data-driven decision-making for traffic engineers and policymakers. The manual serves as a critical tool for ensuring that accident data collected across different jurisdictions is comparable and actionable, facilitating the development of evidence-based countermeasures to reduce bicyclist injuries and fatalities.

Key finding

The Computer Accident Typing system classifies bicycle-vehicle accidents into 44 distinct types using eight coded statements derived from police reports to support traffic safety analysis and countermeasure development.

Methodology

dataset

Provenance

The full processing record for this entry. Every stage of this paper's journey through the pipeline is logged — what ran, with which tool and model, how many attempts it took, and when it last completed. Discovered via bulk_ingest_rosap on 2026-05-23 (6 acquisition events logged).

Summary generated by qwen3.6-27b-prismaquant on 2026-06-10; verification: verified.

Topics

Ranked by relevance to this paper. Hover a topic for its definition.

• motorcycle crash typology
• vru crash typology
• cyclist safety