The film's title, "Highway 301" (which is never mentioned in the film) refers to a U.S. highway that connects Maryland, Virginia and North Carolina, where the Tri-State Gang committed their crimes. According to TCM's Eddie Muller, the gang, led by Walter Legenza (played by Steve Cochran), embarked on their robbery and murder rampage "running roughshod through Pennsylvania, Maryland, and Virginia, though Pennsylvania is not mentioned in the movie.
The armored car robbery described as taking place in Richmond, Virginia, was actually filmed on the ramp to the second floor parking lot in the back of Union Station in Los Angeles. The station's distinctive Southwestern-style Mission Revival architecture and incongruous palm trees in the background give away the substitution.
The picture's armored car robbery was said to take place at Union Station in Richmond, Virginia. Also known as Broad Street Station, it was in operation from 1917 to 1975.
In the Carolina Post headlined "Police Stymied in Welton Shooting", there's a small headline in the lower middle of the screen that reads "110,00 Chinese Living in Trees as Result of Flood". This headline also appears in The Daily Planet in Rescue (1952) and in the Mayberry Gazette Mayberry Goes Hollywood (1961). The headline also has appeared in Doubting Thomas (1935), The Bride and the Beast (1958), the The Three Stooges short The Sitter Downers (1937), I Can't Give You Anything But Love, Baby (1940), The Public Menace (1935), Five (1951), and apparently many other films and TV programs.