City on a county line
Emissions testing in Mustang Ridge: your county decides
The U.S. Census Bureau places the city of Mustang Ridge in Travis and Caldwell counties. About 449 of its residents live in Caldwell County, outside the emissions program (2020 Census): a vehicle registered there needs no emissions test. A vehicle registered in Travis County needs a passing emissions test to renew its registration.
The counties Mustang Ridge lies in
| County | Emissions test | Station fee (max) | Residents in this part (2020) |
|---|---|---|---|
| Travis County | Yes | $11.50 | 495 |
| Caldwell County | No | — | 449 |
City and county boundaries: U.S. Census Bureau TIGERweb (incorporated places whose area overlaps each county; checked 2026-10-06). Residents: 2020 Census blocks inside today’s city limits, an estimate (checked 2026-10-07). The Census map also puts a sliver of Mustang Ridge in Bastrop County (no residents in 2020); parts with fewer than 50 residents are left out of this page.
Motorists with vehicles registered in Brazoria, Collin, Dallas, Denton, Ellis, El Paso, Fort Bend, Galveston, Harris, Johnson, Kaufman, Montgomery, Parker, Rockwall, Tarrant, Travis, and Williamson Counties will not be eligible to renew their vehicle's annual registration if the vehicle has not passed its annual emissions inspection or complied with the vehicle emissions inspection program requirements.
Not required to inspect: electric vehicles, diesel vehicles, motorcycles, and mopeds.
Who this affects
About 449 people live in the part of Mustang Ridge outside the program. If you are one of them and your vehicle is registered at that address, your county has no emissions test. If you move within Mustang Ridge across the county line, the county of the new address applies once the vehicle is registered there. Vehicles that the program does not test anywhere (electric vehicles, diesels, motorcycles and mopeds) are not tested on either side.
Station listings with a Mustang Ridge address
We found no listing with a Mustang Ridge address in a program county that names inspections or emissions testing. See the county pages for nearby stations. The official list is the DPS inspection station locator.
Tax offices for the program counties
Travis County Tax Office
2433 Ridgepoint Drive, Austin, TX 78754-5231
(512) 854-9473
tax-office.traviscountytx.gov
Source: TxDMV county tax office directory.
Mustang Ridge questions
Do I need an emissions test if I live in Mustang Ridge?
It depends on the county your vehicle is registered in. Travis County is in the emissions program; Caldwell County is not.
How do I know which county my Mustang Ridge address is in?
Check the county on your registration renewal notice, or ask the county tax office. A mailing address with the city name can lie outside the city limits, or in a different county.
Sources
- TCEQ, Vehicle Emissions Inspections in Texaspage as published Sep 23, 2026 (archived copy), read Oct 6, 2026
- TxDMV, Travis County Tax Office (TxDMV county tax office directory)read Oct 6, 2026
- U.S. Census Bureau TIGERweb: incorporated places and countiesTIGERweb Incorporated Places (Places_CouSub_ConCity_SubMCD/MapServer/4) intersecting each program county, then counties whose interior overlaps each place (State_County/MapServer/1, esriSpatialRelOverlaps)
- U.S. Census Bureau TIGERweb: 2020 tabulation blocks (population)2020 Census tabulation blocks (TIGERweb Tracts_Blocks/MapServer/2, POP100) of each county that intersect the city's current polygon, kept when the block's internal point lies inside it; parts with fewer than 50 residents are listed as slivers and do not count