OpenHPMS – US Highway Traffic Data Explorer
OpenHPMS is an interactive map for exploring US highway traffic volumes and road performance
data sourced from the Federal Highway Administration's
Highway Performance Monitoring System (HPMS).
Data reflects the 2024 HPMS vintage, submitted annually by state DOTs to the FHWA.
What you can explore
- Traffic volume (AADT) – Average Annual Daily Traffic across interstates, US routes, and state highways.
- Road utilization – Volume-to-capacity ratio indicating how close a segment is to its design limit.
- Heavy vehicle & freight activity – Counts and percentages of single-unit and combination trucks.
- Speed limits and lane counts – Posted speed limits and number of through lanes by segment.
Filter and explore by
State, county, route number, functional classification (Interstate, Principal Arterial), and road type.
What is HPMS?
The Highway Performance Monitoring System is an annual data collection program administered by the FHWA.
State DOTs report geometric, operational, and traffic data for a sample of road segments across the
National Highway System and lower functional classes. AADT — Average Annual Daily Traffic — is the
primary traffic volume metric, representing the estimated total yearly vehicle count divided by 365.
Technology
Built with FastAPI, SpatiaLite, React (Vite), Deck.gl, and MapLibre GL.
Enable JavaScript to use the interactive map.