DOT NHTSA - CRSS Sampling Operations Resource Center - MRAS

The Department of Transportation (DOT), through the General Services Administration (GSA), is seeking to conduct market research for the National Highway Traffic Safety Administration (NHTSA). NHTSA plays a crucial role in reducing personal and property losses resulting from motor vehicle crashes by utilizing comprehensive data systems. These systems are vital for conducting basic research, identifying problem areas, and developing effective countermeasures. The goal is to ensure improved highway safety by accurately assessing and implementing programs, rules, standards, and new technologies.

This solicitation focuses on the Crash Report Sampling System (CRSS), which is integral to NHTSA's efforts in collecting record-based data on motor vehicle crashes. CRSS captures a sample of police-reported crashes involving vehicles, pedestrians, and cyclists. This data ranges from minor property-damage incidents to fatal accidents. The information gathered through CRSS is used extensively by NHTSA and other stakeholders to estimate crash statistics, identify safety issues on highways, track safety trends over time, inform consumer initiatives, and perform cost-benefit analyses related to highway safety regulations.

The CRSS employs a sophisticated multi-stage stratified sampling methodology. Initially, it involves the selection of Primary Sampling Units (PSUs) from 3,117 counties grouped into 707 PSUs across the country. These PSUs are selected using a probability proportional to size (PPS) method based on various factors such as urbanicity and vehicle miles traveled. In subsequent stages of sampling within selected PSUs, police jurisdictions are stratified based on crash counts across several categories of interest. This structured approach allows NHTSA flexibility in adjusting sample sizes without needing new selections while maintaining statistical reliability.