Traffic data, which includes counts and speeds, is usually collected as part of a traffic monitoring program, which is required for all State highway agencies. Well-designed traffic monitoring programs support all aspects of highway planning, design, operations, and maintenance including safety considerations in all phases. The Traffic Monitoring Guide (TMG) documents policies, standards, procedures, and equipment used in a traffic monitoring program with a view toward the future of traffic monitoring practices. The TMG also provides guidance to highway agencies in the methodologies and approaches used to collect, analyze, and report traffic data for their jurisdictions. The TMG is organized in seven chapters:

• Traffic Monitoring Theory, Technology, and Concepts.
• Traffic Monitoring Program – Business Planning and Design.
• Traffic Monitoring Methodologies.
• Traffic Monitoring for Non-Motorized Traffic.
• Transportation Management and Operations.
• HPMS Requirements for Traffic Data.
• Traffic Monitoring Formats.

The purpose of the TMG is to provide a resource for States to manage and improve their traffic monitoring programs with considerations for all business needs that use traffic data, and is written to assist novice through expert users. The TMG presents methodologies to collect traffic data and improve the quality and coverage of data using proven and innovative technologies, as well as methods to estimate traffic and AADT.

The TMG also outlines the highway performance monitoring system (HPMS) data requirements and the various formats for traffic data.