The Traffic Data Collection & Analysis (TDCA) section is responsible for collecting traffic data on approximately 5,800 active short-term traffic count sites statewide. These counts, also known as coverage counts, make up the bulk of the Department's traffic count program. The continuous count program currently has a total of ninety-nine permanent counters, sixty-two Automatic Traffic Recorder (ATR) sites and thirty-seven Weigh In Motion (WIM) sites throughout the state of Montana collecting traffic data on a daily basis. In addition to providing volume information, a significant number of ATRs and WIMs provide information such as vehicle length, classification, truck weight data and unbiased speed data.
The primary purpose of permanent counters is to obtain information for:
- Seasonally adjusting short term counts to estimate Annual Average Daily Traffic (AADT);
- Providing generalized peak and design hour factors for highway geometric design;
- Monitoring monthly and annual traffic trends;
- Providing long term growth factors.
If you have questions or concerns, of if you are planning or currently working on a project that might potentially impact an ATR or a WIM site, please contact Becky Duke at 406-444-6122 or .