Blood alcohol concentration (BAC) is a measure of the percentage of alcohol in a person's blood. The higher the BAC, the more impaired a person is.

Most work zones have signs alerting you to reductions in the speed limit through the work zone. The reduced speed limits are usually clearly posted within the work zone, but if there are no reduced speed limit signs, you should obey the normal posted speed limit.

This sign warns a driver of a change in direction or a narrowing of the road. A driver may find several of these signs on the outside of a sharp curve or on approaches to a narrow bridge.

This orange warning sign tells drivers that an area of roadwork is upcoming. When traveling through a work zone, stay alert for temporary traffic control devices.

When parking uphill on a road that has a curb, your wheels should be turned away from the curb. When parking uphill on a street without a curb or when parking downhill, your wheels should be turned toward the curb or edge of the road.

It is illegal to cross the centerline to pass when driving on hills, in curves, and in other locations where you cannot see ahead far enough to pass safely. You may not pass at street crossings, at railroad crossings, where signs indicate no passing zones, or where a solid yellow line is next to your lane. You may not pass when the vehicle in front of you has stopped for a pedestrian or when driving in work zones where passing would be hazardous.

Pavement is particularly treacherous when it first begins to rain. Accumulations of dirt and oil mix with the rainwater, creating a greasy film on the roadway.

Orange, diamond-shaped signs are used to mark construction, maintenance, survey, and utility work areas. These signs help direct drivers and pedestrians safely through dangerous zones. Fines for traffic convictions may double in areas marked by these signs.

Fatigue causes errors related to speed and distance, increases your risk of being in a crash, and causes you to take more time to make decisions. When you are fatigued, you could fall asleep behind the wheel and crash, injuring or killing yourself or others.

You must never turn around while on or near any curve or hill. You may not be able to see oncoming traffic or pedestrians and may cause a collision.

When stopping your vehicle on the roadway, first check your mirrors for traffic. Be aware of surrounding drivers as you release the accelerator and allow your vehicle to slow. Move your foot to the brake pedal and press with steady pressure for a smooth stop.

This sign prohibits right turns. It is illegal to turn right at an intersection where this sign is posted.

A broken yellow centerline next to your side of the road indicates that traffic may cross the centerline to pass from your side of the road.

Alcohol takes effect quickly and is slow to leave your system. Cold showers, black coffee, and exercise will do nothing to reduce a person's blood alcohol content (BAC). The only way to lower your BAC is to wait.

When parking on a hill, you should always leave your vehicle in gear or in the "park" position. If there is no curb, you should turn your front wheels so that the vehicle will roll away from the center of the road if the brakes fail. If there is a curb, the front wheels should be turned toward it (if headed downhill) or away from and gently touching it (if headed uphill).

"No zones" are areas around trucks or buses in which cars disappear into the larger vehicle's blind spots. "No zones" can also be defined as areas in which cars are so close to the larger vehicle that they restrict the truck or bus driver’s ability to stop and maneuver safely. A car being in a "No zone" greatly increases the potential for a crash.

You are driving defensively when you are looking down the road for potential hazards. Constantly staring at the road directly in front of your vehicle is dangerous. As you scan ahead, be alert to vehicles around you.

When driving, watch for warning signs of fatigue. You are too tired to drive safely if you are struggling to keep your eyes open, drifting from your lane, or turning up the radio and rolling down your windows to keep yourself awake. If you notice these signs, it is a good idea to find a safe place to park so you can refresh yourself with a short nap.

This sign indicates that you may not make a U-turn. You cannot turn around to go in the opposite direction at an intersection where this sign is posted.

Warning signs are usually yellow with black markings. Warning signs may alert drivers to areas where animals, people, and vehicles are likely to cross traffic.

When following a motorcyclist, allow for at least a three- to four-second following distance. Motorcycles can stop quickly and following them too closely endangers your life and that of the motorcyclist. If the motorcyclist should fall, you need extra distance to avoid the rider. The chances of a fall are greatest on wet and icy roads, gravel roads, and metal surfaces such as bridges, gratings, and streetcar or railroad tracks.

This sign prohibits drivers from making a U-turn. You cannot turn around to go in the opposite direction at an intersection where this sign is posted.

When changing lanes, glance over your shoulder to check for traffic in your blind spot. You may need to look several times before changing lanes. You must keep track of what traffic is doing in front of you as well as what traffic is doing in the lane next to you.

An octagonal (eight-sided) sign always means "Stop." Come to a complete stop, yield to traffic and pedestrians that have the right-of-way, and proceed when the way is clear.

When passing another vehicle, move back into your original lane only when you can see the passed vehicle’s headlights in your rearview mirror. This ensures that you will have enough room to safely pull back in front of the other vehicle.