Peak hour on-system congestion maps
Reference maps
Calculation method
TxDOT created the car-space method to calculate the space between cars in one mile increments, factoring:
- Number of lanes.
- Annual average daily traffic (AADT).
- Percentage of trucks.
- Average car length.
The calculated space between cars is categorized to illustrate levels of congestion.
This map series is updated annually, typically mid-summer, following the publication of end-of-year data from the previous calendar year.