Warning signs are usually yellow with black markings. They alert you to conditions that are immediately ahead. This sign warns drivers that the number of lanes is reduced ahead and that traffic should merge left.

This sign warns drivers that the divided highway ends ahead.

Large trucks take longer to stop than other vehicles traveling at the same speed. The average passenger vehicle traveling at 55 mph can stop within 400 feet. However, a large truck traveling at the same speed can take almost 800 feet to stop.

If you drive past these signs, you are going the wrong way and are at risk of a head-on collision. You should cautiously turn around.

If you experience a tire blowout, do not immediately apply the brakes. Grip the steering wheel firmly and steer to remain in your traffic lane. Reduce your speed gradually by releasing the accelerator and staying off the brakes. Once you are moving very slowly, apply the brakes lightly and pull off the road into a safe area.

Your emotions affect your ability to drive safely. If you are overly angry, excited, afraid, worried, or depressed, you should give yourself time to calm down before operating a vehicle. You need to be able to mentally focus on driving without thinking about the things that made you upset.

Diamond-shaped signs are used to warn drivers about upcoming hazards or special conditions. Construction areas are usually indicated by orange-colored warning signs.

Even if the light is green, you may not enter an intersection unless you can get completely across before the light turns red. If you block the intersection, you can be cited.

This sign indicates the presence of a pedestrian crossing. You should watch for people entering a crosswalk or crossing your path. Slow down and be prepared to stop.

Signs with a red circle and diagonal line over a black symbol indicate that the action represented by the symbol is prohibited. In this case, the sign indicates that left turns are prohibited.

Always be prepared to yield to any oncoming trains before crossing railroad tracks, particularly if there are no lights or gates controlling the crossing. Never start to cross the tracks until there is room for your entire vehicle on the other side of the tracks. Due to the risk of a vehicle stalling, it is not wise to shift gears when crossing railroad tracks.

Lane usage for the motorcyclist is critical. Motorcycles are entitled to the same full lane width as all other vehicles.

Double parking is when a driver parks on the roadway side of another vehicle that is already parked next to a curb. Double parking a vehicle is prohibited because it blocks traffic and may cause an accident.

The average person’s body will process about one alcoholic drink in one hour. However, many factors play a part in determining how impaired a person will become when consuming alcohol, including the amount of alcohol consumed, how fast it is consumed, and a person’s body weight, food intake, and general health.

When changing lanes or turning, signal your intentions well in advance. The law requires that you signal for at least 100 feet before you move your vehicle to the right or left. Before pulling away from a curb, always signal to inform passing drivers of your intentions.

Motorcycle operators have the right to use a complete traffic lane. Two motorcyclists may share a lane, but a car should never try to share a lane with a motorcycle.

Diamond-shaped signs are used to warn of actual or possible hazards. The color orange is used for warning signs usually found in construction or maintenance areas.

To prevent skidding on slippery surfaces, you should shift to a low gear before going down a steep hill. You should also follow farther behind the vehicle in front of you than you normally would. Quick stops should be avoided. Unless you have antilock brakes, pump the brakes to slow or stop.

This sign warns that pavement is slippery when wet. In wet conditions, you should reduce your speed, avoid braking or changing direction suddenly, and increase the distance between your vehicle and the one ahead.

When passing a vehicle that has just parked parallel to the road, you should assume the driver will open the door as you approach. Use extra caution when driving near parked vehicles.

This sign indicates that a roundabout is ahead. Enter a roundabout at a low speed and yield to existing traffic.

The only method that effectively reduces your BAC is to not drink alcohol for a period of time. Coffee, exercise, and cold showers cannot reduce your BAC or change the effects of alcohol. They can help you remain awake, but they cannot change your BAC or make you sober.

You should adjust your speed to travel smoothly with the other traffic on a roadway (provided that the other traffic is driving within the posted speed limits). Remember that vehicles moving in the same direction at the same speed cannot hit each other. Crashes involving multiple vehicles often happen when some vehicles are traveling at different speeds than others.

A green arrow means "go." You must turn in the direction the arrow is pointing after you yield to any vehicles, bicycles, or pedestrians who are still in the intersection.

It is illegal to make a left turn on a red traffic signal in the District of Columbia. You may make a right turn on a red traffic light where permitted.