Classification counts determine the breakdown of the 13 FHWA vehicle categories, per the TxDOT Traffic Recorder Instruction Manual. Classification counts are similar to segment traffic counts and include two-way traffic volumes on a roadway for a specified period of time greater than 24 hours but less than a year. Classification counts help determine the percentage of different vehicle categories using a roadway, which is important in performing traffic operational analysis and pavement design. It is suggested that classification counts be conducted during a typical week for a period of seven consecutive days for projects needing microsimulation on an IAJR project. Classification counts are to be conducted for a minimum of 48-hours for other projects, based on coordination with the TxDOT project manager. For locations where classification counts are performed in place of segment traffic counts, it is suggested the segment traffic collection method be used.

Suggested classification counts collection method: