Map of Texas

Texas, the second-largest state in the Union, has the most state highway miles in the country.

Photography contributions by Alex Nitzman, Andy Field, Brent Ivy, Jeff Royston, Justin Cozart and Kevin Trinkle. Many thanks to Kevin, who both started Lone Star Roads on AARoads in 2005 and compiled the bulk of the original Texas highway guides found throughout the site.

Photo Guides

What is a FM Road?

A Farm to Market Road (FM) is a secondary state highway. The system was conceived in the 1930s as part of a “Good roads” project to ensure farms (or ranches) have all-weather access to markets. The system was originally funded by an earmark from the general fund with state funds (no federal funds). Some FM roads are eligible for federal aid, however.

There is no difference between a FM, Ranch to Market (RM) or Urban Road (UR) for state purposes. RM markers are generally found in Western Texas where ranches are dominant, while FM roads are generally found in eastern Texas where farms dominate. There are some exceptions to this general rule though.

Urban Roads were originally FM roads (most notably around Houston and San Antonio) but were reclassified in 1995 to UR status (since they do not serve farms anymore). All are still signed as FM roads to avoid driver confusion and save costs involved in re-signing the road.

Texas Highway Designations

TxDOT classifies Interstates. U.S. Highways, State Highways and other routes across the state with two letter abbreviations. The full list can be found at the TxDOT web site. A summary of those commonly used on AARoads include:

  • IH – Interstate Highway
  • SH – State Highway – includes the lettered routes for Old San Antonio Road (OSR) and NASA Road 1
  • SL – State Highway Loop
  • SS – State Highway Spur
  • UR – Urban Road – a farm or ranch to market road routed within an urban area.
  • RM – Ranch to Market Road – generally used in rural areas of the state
  • PR – Park Road – a state maintained roadway to a state or national park

Other terms referenced in the TxDOT Designation Files (route log for all state maintained roadways):

  • BI – Business Interstate Highway
  • BU – Business US Highway
  • BS – Business State Highway
  • BF – Business Farm to Market Road
  • RE – Recreational Road
  • UA – U.S. Highway Alternate
  • UP – U.S. Highway Spur

Farm and Ranch to Market Roads may have Spur routes posted as well.

Population Statistics

State Population
Metropolitan Populations
Dallas-Fort Worth-
7,637,387 Houston-The Woodlands-
Sugar Land
7,122,240 San Antonio-
New Braunfels
Austin-Round Rock-
2,283,371 McAllen-Edinburg-
870,871 El Paso 868,859
Killeen-Temple 475,367 Corpus Christi 421,933 Brownsville-
Top County Populations
Harris 4,731,145 Dallas 2,613,539 Tarrant 2,110,640
Bexar 2,009,324 Travis 1,290,188 Collin 1,064,465
Denton 906,422 Hidalgo 870,781 El Paso 865,657
Top City Populations
Houston 2,316,120 San Antonio 1,567,118 Dallas 1,343,266
Austin 995,484 Fort Worth 927,720 El Paso 681,534
Arlington 398,864 Corpus Christi 327,248 Plano 291,296
Sources: 2020 U.S. Census Data (metro populations and counties), 2020 U.S. Census Estimate (cities)

Updated February 27, 2023.