AASHTO GTDP-2

The objective of the second edition of these guidelines is to improve the quality of the traffic information that supports decisions at all levels of the transportation profession. Traffic data programs are essential for state Departments of Transportation to accomplish their mission of ensuring safety and mobility to the traveling public. Traffic data supports capital investment programs and budgets, as well as effective design and maintenance programs. This document is a reference for professional traffic monitoring and establishes recommended national traffic monitoring practices that reflect current practice and advances made in the past several years. Since publication of the first edition of the guidelines in 1992, many advances have been made in traffic monitoring procedures, and updated editions of the TMG were published in 1994 and 2001. The guidebook is intended for use by state and local transportation agencies, as well as others involved in traffic data programs.