A Highway Patrol trooper investigates a crash near Austin in 1974. DPS Director Homer Garrison (on the far left) and several unknown law enforcement officers demonstrate an early breath alcohol test (circa 1938). DPS trooper demonstrating mobile communications technology (circa 1940s). Texas Highway Patrol troopers patrolled Texas highways on motorcycles in the 1930s and 1940s. A Texas Highway Patrol trooper helping a stranded motorist who ran out of fuel.