Next tonight here, to an ABC news investigation. We've all had it happen before. One of those rigs racing past us on the highway. ABC's Matt Gutman this evening, flying overhead with the authorities.... See More
Next tonight here, to an ABC news investigation. We've all had it happen before. One of those rigs racing past us on the highway. ABC's Matt Gutman this evening, flying overhead with the authorities. How fast are some of those truckers really going? Reporter: We're with the Ohio state police, in the sky -- Real dark blue, white box. Following too close. Reporter: And on the black top. In hot pursuit of reckless truckers. Reporter: We are flying right now, trying to catch up. They caught you going 77 miles an hour and tailgating behind a car. You think it's hazardous? Yes. Reporter: In 2012 alone, there were over 300,000 large truck crashes in the U.S., with over 4,000 fatalities. Police warn of a particular danger. Tired truckers. We got a bit of a problem, dude. Reporter: Just listen what happened to this trucker on a frigid February night. I'm starting to fall asleep going down the road here. Here's the deal. Get some kof feoff and let's -- we don't have a choice on this. Reporter: Yep, that dispatcher is ordering a trucker who says he's too tired to drive to get back on the road. You wonder where your paycheck went this week? You know, it came down to where it went tonight. Are we clear on that? Reporter: The company refuses to talk to us, but we got a very clear response from the head of the trucking lob bi. Well, the driver was obviously doing the right thing and the dispatcher was obviously doing the wrong thing. There's just too much at stake. Reporter: He later quit. His record and his conscience intact. Matt Gutman, ABC news, Miami. Matt will have much more on "20/20" tomorrow night.
This transcript has been automatically generated and may not be 100% accurate.