Abstract
This paper ls a discussion of an in-depth evaluation study of highway data development and analysis activities of the Washington State Department of Transportation. Statistically based procedures and recommendations that were developed to streamline the highway data collection program are described. Opportunities to reduce manpower and equipment costs, streamline work activities, Improve the quality of data collected, and provide accurate and timely data for the various users were Identified. Given the focus on highway data, a major effort was devoted to the department’s traffic-counting program. However, many data items and programs were considered, and the following items received particular attention: traffic volume counting, including estimation of annual average dally traffic at any location tbroughout the state highway system; associated seasonal, axle, and growth factors; vehicle classification; trqck weight; and the relationships between the statistical sampling requirements recommended for these items and those associated with the FHWA Highway Performance Monitoring System (HPMS) in the state. Employing statistical sampling methods that complement the HPMS sample offers a strong potential for significantly Improving the cost-effectiveness of a statewide highway data collection program.