The Manitoba Department of Highways and Transportation requires a variety of traffic volume and other statistics on the usage of provincial highways. This paper describes a review of the Department's former traffic data collection system and the design, development, and implementation of a new traffic information system. The research includes: (1) characterization of traffic data systems generally and the former Manitoba traffic monitoring system in particular; (2) formulation of performance criteria for the system based on general principles of data collection, definition of particular data needs in Manitoba, and technical criteria related to efficiency and effectiveness; (3) an evaluation of the former data collection program against these performance criteria; and (a) the design and implementation of numerous improvements to the system to address the identified shortcomings. Key components of the new system are a new method of specifyng traffic pattern groups and a "factorless expansion" process for expanding short-term traffic counts to estimates of average annual daily traffic.