Instructions given by police officers directing traffic always override posted traffic signals and signs. Follow the officer's instructions.

To avoid the dangers of fatigued driving, take breaks every hour or so during a long trip. If possible, share driving responsibilities with another person so you can each sleep while the other person drives.

With decreased visibility and the glare of oncoming headlights, you cannot see as far ahead at night as you can during the day. Always use headlights and exercise caution when driving in the dark.

You may drive more slowly than the posted speed limit, based on road conditions, but it is illegal to drive any faster than the posted speed limit. Some conditions which require reduced speed for safety include approaching curves or hills where visibility is limited, driving on slippery roads, and driving on roads where animals and pedestrians are present.

Always be aware of what is happening around your vehicle. Constantly observing your surroundings to the front, sides, and rear of your vehicle will help you see problems that may require you to change speed or roadway position.

A solid yellow arrow means that the protection of a green arrow is ending. If you are turning in the direction of the arrow, you should prepare to stop and yield the right-of-way to oncoming traffic before turning.

If your vehicle is hit from the rear while you are in forward motion, your body will be thrown backward. Press yourself against the back of your seat and put your head against the head restraint to prevent whiplash. Maintain a firm grip on the steering wheel and be ready to apply your brakes to avoid being pushed into another vehicle.

When passing is permitted, look for both headlights of the passed vehicle in your rearview mirror. Only then may you safely return to your original lane.

If you are being followed too closely while driving in the left lane of a multilane roadway, merge to your right to allow the other car to pass. The far left lane on a multilane road is intended for use by faster-moving vehicles passing slower traffic.

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.

At intersections with stop signs on all corners, cars should proceed in the order that they arrive. Come to a complete stop and yield the right-of-way to any vehicle that arrived to the intersection before you.

Warning signs are usually yellow with black markings. These signs alert drivers to areas where bicycles may be crossing.

You should always signal when moving your vehicle to the right or left. On an interstate, you should stay in the right lane if you are moving more slowly than the surrounding traffic. It is illegal to back up or make a U-turn on interstate highways, so if you miss your exit, you should proceed to the next exit.

This sign indicates parking spaces that are reserved for vehicles displaying Persons with Disabilities license plates, Disabled Veteran license plates, and/or disabled parking placards.

A triangular red and white sign indicates that you must yield the right-of-way.

Warning signs provide notice to road users of a situation that might not be readily apparent and are usually yellow with black markings. This sign warns drivers to be careful when driving under wet conditions as the pavement will become slippery and more difficult to navigate safely.

You must approach all railroad crossings with extreme caution and cross only when you know that no train is coming from either direction. Be aware of vehicles that must stop at all railroad crossings, such as school buses and trucks carrying hazardous materials.

You should always signal when turning, changing lanes, slowing down, or stopping so that other drivers, motorcyclists, bicyclists, and pedestrians will know your intentions.

This sign indicates that turns in the direction of the arrow (in this case, to the right) are prohibited.

Warning signs are usually yellow with black markings. They alert you to conditions that are immediately ahead. This sign indicates that there is a steep hill ahead. Slow down and be ready to shift to a lower gear to control your speed and protect your brakes from damage.

If you are in an intersection when you see an emergency vehicle approaching while using its flashing lights and/or siren, continue through the intersection and then drive to the right and stop. You must yield the right-of-way to any police vehicle, fire engine, ambulance, or other emergency vehicle using a siren or flashing lights.

Pedestrians have the right-of-way at street crossings but must obey traffic control signals. Where a traffic signal is not present, vehicles must stop for pedestrians in a crosswalk, whether it is marked or unmarked.

Warning signs are usually yellow with black markings. This sign indicates that there is a steep hill ahead. Slow down and be ready to shift to a lower gear to control your speed and protect your brakes from damage.

Legal prescription and over-the-counter drugs can impair your ability to drive, including drugs taken for colds, hay fever, allergies, or to calm nerves or muscles. It is illegal to drive while under the influence of any drug that impairs your ability to drive safely; this law does not differentiate between illegal, prescription, or over-the-counter drugs.

Regulatory signs inform drivers of specific laws that must be obeyed. Displayed laws may be about traffic direction, lane use, turning, speed, parking, or special situations. Regulatory signs are commonly white squares or rectangles with black, red, or green letters or symbols.