A turning movement count records how road users move through an intersection, including turning and through movements.
Definition
A turning movement count is field data that records movements through an intersection, commonly including left turns, right turns, and through movements. The scope may also include vehicle types, pedestrians, or cyclists, and it identifies the selected collection periods and conditions. Results are inputs to operational or planning analysis, and their usefulness depends on location, timing, method, and data quality. Firms may specify different movement categories, intervals, and reporting formats, so the project scope should make these clear. A turning movement count is not a general measure of all travel demand and does not itself determine intersection capacity or safety. Analysts may make adjustments when the method and project requirements support them. It differs from a traffic count that does not break movements down by direction through the intersection. The ASCE professional resource provides general context for transportation engineering work.
How owners use it
- Specify movement categories, collection intervals, locations, periods, and quality checks in the field scope.
- Confirm whether pedestrian, cyclist, and vehicle classification data are needed for the intended analysis.
- Use counts as documented inputs to intersection operations or planning work.
- Example: If 120 vehicles turn left, 280 go through, and 100 turn right in a period, total counted movements are 120 + 280 + 100 = 500.
