There has been much fun made of the part played by Broderick Crawford---and much denigration accorded the show in general. I have a complete collection of the series. I watch them when I need a fix from the current workaday world of crime now overwhelming law-enforcement...and the courts allowing it to happen.
Crawford, whose mom and dad worked the Vaudeville circuit, was a very talented and forceful visage in "Highway Patrol". One didn't have to look like Clark Gable in order to portray a dedicated cop. No, he wasn't pretty. Yes, he looked like an unmade bed. But, that just added authenticity to the show in my 15-19 year old (at the time) eyes.
I would have hated being interrogated by him even if I hadn't done anything wrong. Think about how much more latitude the first line of law-enforcement had during that show's time. It started four years before the passage of the Miranda Act. Folks who got too chirpy with "the law" in those days, learned a pretty good lesson before they even got locked up. Wish it still held true. Buddy Buchanan