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.