Mr. Brent decided to pass a large, slow-moving truck against a double-solid line. After overtaking the truck, the scene through the front window of the car shows that the right size of the road is marked with a series of white poles. He is immediately nabbed, but when he pulls over with the trooper behind him, the edge of the road is "soft-shouldered" without poles or even paint marking the edge of the road.
The checkpoint officers were instructed to check everything on the cars, including lights, wipers, etc. In the next scene and several after that, officers are seen barely checking licenses and passing the cars on. No physical checks of the cars are shown.
When Harry Brent was on his way to Overland City, in the beginning of show, the mileage on his odometer is 2041.4. When he is going slowly behind the truck odometer shows 2048.5.
When Harry and Clara leave the Tip Top Cafe, Harry is driving. Clara is telling him to slow down, the camera pans to speedometer....the odometer shows 2041.7. The fuel gauge is similar, just above empty on all shots. They obviously reused a shot from earlier.