The highway is usually used as a reliever route for local traffic between the two cities, as opposed to I-20 a few miles to the south.

In the eastern part of the city, SH 191 crosses by Music City Mall and the University of Texas at the Permian Basin and picks up freeway status at the eastern leg of Loop 338.

The highway exits the Odessa city limits and enters into Midland County.

SH 191 was originally designated on November 28, 1932, on a route from Albany south to Coleman.

Spur 492 was designated on June 4, 1970, from Loop 338 westward to Grandview Avenue, replacing FM 2399 and extending the road 0.5 miles (0.80 km) west.