Talented Daniel Mainwaring ("Invasion of the Body Snatchers" (1956)) co-authored this rather farfetched story of an insurance detective (Charles McGraw) and a cool vamp (Joan Dixon), who turns his head and heart. Hard boiled tales like this were common in the post-war years, both in B pictures and pulp fiction. Romance is not what we usually expect from ruggedly handsome tough guy McGraw, but he does the job, veering deftly from sap to hood. "Rafferty" a/k/a "The Beautiful Trap" by Bill S. Ballinger was the best example of this genre, but "Roadblock" maintains suspense and 73 minutes is not too much of an imposition: the climactic high speed car chase is worth the wait. The supporting cast and DP Nicholas Musuraca are more than adequate.