When entering the interstate on a short entrance ramp where there is no acceleration lane, speed up only after you have identified a gap in traffic. In general, you should be stopped while waiting for a gap to appear.

Anytime you want to merge with other drivers, you need to find a gap large enough for you to safely enter into the flow of traffic. You should not stop on the entrance ramp to an interstate highway unless there are no gaps into which you may safely merge.

When being tailgated, create extra space in front of your vehicle and do not brake suddenly. Slow down gradually or merge into another lane to prevent a collision with the tailgater.

You should increase your following distance when you are behind a large vehicle that blocks your vision, when driving in bad weather or heavy traffic, when exiting an expressway, when behind a motorcycle or bicycle, and if someone is tailgating you.

Anything that causes you to take your attention away from driving, take your eyes off the road, and/or take your hands off the wheel is a distraction.

You may never drive off the paved or main-traveled portion of the road and onto the shoulder to pass another vehicle.

You must yield to any transit vehicle that is signaling to pull back onto the main roadway after it has stopped to load or unload passengers. Change lanes, slow down, or stop to allow the bus safe re-entry into traffic.

When approaching an intersection with a solid yellow traffic light, slow to a stop before entering the intersection, if it is safe to do so. If you can't stop safely, drive carefully through the intersection.

Use high beam headlights only when driving in rural areas and when other cars are not nearby. Lower your headlights to their low beam setting when you are following closely behind another driver.

Before you enter an intersection, look to both the left and right for approaching vehicles or crossing pedestrians. Look to your left a second time, as vehicle approaching from your left will be closer than those approaching from your right. Look across the intersection before you start to move to make sure the path is clear all the way through.

Diamond-shaped signs are used to warn drivers of special conditions or hazards ahead. They are typically yellow or orange in color.

District of Columbia law requires drivers and all passengers to wear seat belts in passenger cars, trucks, tractors, multi-purpose vehicles, and passenger buses. These vehicles may not be operated unless the driver and each occupant is wearing a seat belt.

Slow-moving vehicles, such as farm tractors, road maintenance vehicles, and animal-drawn carts, display an orange and red triangle on the back.

For drivers age 21 or older, it is illegal to operate a motor vehicle with a blood alcohol concentration (BAC) of 0.08 percent or higher. Driving while under the influence of alcohol is not only illegal, but dangerous.

Hydroplaning occurs when there is standing water on a roadway. At speeds up to 35 mph, most tires will channel water away from the tire. As your speed increases past 35 mph, tires cannot channel the water as well and your tires may start to lose contact with the road and ride over the water like a set of water skis.

Your horn should be used to warn other drivers or pedestrians in situations where they may not see you. For example, if you think another driver is about to hit you, you should sound your horn.

A steady downward green arrow over a traffic lane means you may use the lane indicated.

Before passing, you should signal early enough for other drivers to know your plans in advance.

On a traffic signal arranged vertically, red is always on top and green on the bottom. When arranged horizontally, red is always on the left and green on the right.

To avoid the need for last-minute braking or turning, consistently watch the road far ahead of your vehicle. By looking ahead and being ready to stop or change lanes if needed, you can drive more safely, save fuel, and help keep traffic moving at a steady pace.

This sign warns of a winding road ahead.

If an emergency vehicle using its lights or siren approaches while you are driving on a one-way street, you must drive toward the nearest roadside and stop.

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.

Emotions can have a great effect on your driving ability. You may not be able to drive well if you are overly worried, excited, afraid, angry, or sad. Stress can lessen your concentration on the task of driving. It is better to wait to drive than to risk driving while you are emotionally unstable.

This is a speed limit sign. It indicates the maximum legal speed that you may drive on the road where it is posted. At times of rain, snow, ice, or other less-than-ideal conditions, you may have to drive more slowly than the posted limit.