The sign shows that there is a steep descent ahead. It's important to watch out for descending vehicles and to use a lower gear to decrease wear on your brakes.

A flashing yellow light warns you to be careful. You should slow down, stay alert, and proceed with caution.

Before switching lanes, you should not flash your headlights. It's the visual equivalent to sounding your horn and it can confuse other drivers.

You can only make a U-turn to cross a double solid yellow line. U-turns are not allowed on limited-access expressways, in school zones, near the top of a hill, on a curve, or where there are "No U-Turn" signs.

In several states, like New York and Pennsylvania, you need to park at least 15 feet away from a fire hydrant to ensure that emergency personnel has enough space to obtain water in the event of a fire.

It is illegal to walk, drive, go under, or around a lowered crossing gate. It's also illegal to ignore the flashing lights posted at a railroad crossing.

At roundabouts, the traffic circulates counter-clockwise and the vehicles move toward the yield line.

The do not enter sign is a regulatory driving sign often encountered on the road. You should not enter the road, exit ramp, or crossover where the sign is posted.

Unless there are signs or markings indicating otherwise, you should turn from the right lane of the road you are on to the right line of the road you're turning onto.