This sign warns of the possible presence of merging traffic.

When driving in fog, you should slow down and use your low beam headlights. If the fog is so bad that you cannot see, pull off the road and wait for the fog to clear.

It is best to postpone driving until a fog clears. However, if you must drive in the fog, you should do so slowly and use your windshield wipers and low beam headlights.

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.

A person with a Class C license may drive a three-axle vehicle if it weighs 6,000 pounds or less.

It is never a good idea to leave a child unattended in a car. It is illegal to leave a child age six or younger unattended in a vehicle. A child may be left under the supervision of a person age 12 or older.

Collisions are more likely to happen when one driver moves faster or slower than the other vehicles on the road. Driving faster than other traffic increases your chance of being involved in a collision. Driving more slowly than other traffic is also dangerous because it can increase the risk of a rear-end collision with your vehicle or cause other drivers to swerve to avoid hitting you.

A left turn against a red light can only be made from a one-way street onto a one-way street. Signal and stop for a red traffic light at the marked limit line.

If making a right turn, you may enter the bicycle lane no more than 200 feet before the corner or driveway. Drivers of motor vehicles should not enter a bicycle lane at any other time.

Use your low beams when driving in fog, snow, rain, or mist. Light from high beams will reflect off of precipitation, causing a glare and making it even more difficult to see. Some vehicles are equipped with fog lights that should be used in addition to low beam headlights.

Alcohol slows your reflexes and reaction time, reduces your ability to see clearly, and makes you less alert. As the amount of alcohol in your body increases, your judgment worsens and your driving skills decrease. You will have trouble judging distances, speeds, and the movement of other vehicles.

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.

It can be hard to judge the speed of oncoming vehicles. They do not always seem to be coming as fast as they really are. Always be sure you can safely change lanes when passing on a two-lane street. If you are not sure of an oncoming vehicle's speed, wait to pass until the oncoming vehicle has passed and you are sure there is enough space for you to change lanes safely.

If you approach a stopped school bus that has its lights flashing and arm extended, you must come to a full stop and remain stopped until the signal arm is pulled back and the bus resumes motion. This law applies whether you are traveling in the same direction as the bus or if you are approaching from the opposite side of the street.

Any time you come to a place where people may cross or enter your path, or where one line of traffic meets another, you should look to the left and right sides of your vehicle to make sure no one is coming.

Bicycles are considered vehicles when used on roadways. Bicyclists and motorists are expected to follow the same rules of the road.

Warning signs are usually yellow with black markings. This sign warns drivers that the roadway will be slippery when wet and they should reduce their speed accordingly.

If you are driving and come across an animal of any kind in the road, try to slow down and stop if it's safe to do so. Swerving to avoid an animal can be dangerous because your vehicle may lose control and cause an accident.

Pentagonal signs mean you are approaching a school zone and/or school crossing. When you see these signs, be alert and prepare to stop.

In California, it is illegal to smoke in a vehicle at any time when a minor is present.

Yellow lines mark the center of a road used for two-way traffic. A solid yellow centerline indicates that drivers may not cross the line to pass. A broken yellow centerline indicates that drivers may cross the line to pass, but only if passing would not interfere with traffic.

Never assume other drivers will give you the right-of-way. Yield your right-of-way whenever it helps prevent collisions.

Tailgating is a common behavior that can lead to aggressive driving, and so it should be avoided. Drivers may face legal consequences for driving unsafely.

When you are making a right turn, you must enter the bicycle lane no more than 200 feet before the corner or driveway entrance. Do not drive a motor vehicle in the bicycle lane at any other time.

U-turns are permitted in residential areas if there are no vehicles approaching within 200 feet. They are also permitted when a traffic sign, light, or signal protects you from approaching vehicles.

Solid yellow lines on two-lane roads indicate zones where passing is prohibited. If a solid yellow line appears next to a broken yellow line, drivers in the lane nearest to the solid yellow line may not pass. In some instances, both yellow lines will be solid, indicating that it is not safe to pass from either direction.

A locked wheel skid is most commonly caused by a driver braking too hard while traveling at a high speed. Drivers should use their brakes smoothly and gradually.

If your vehicle enters a skid, you should take your foot off of the brake and steer in the direction that you want to go. For example, if the rear of your vehicle is skidding to the left, you should steer to the left. This will help bring the front of the vehicle in line with the rear, thereby straightening out the vehicle's overall direction.

Yellow lines separate traffic moving in opposite directions. Dashed lines on the pavement indicate that passing is permitted when safe.

At a yield sign, you must slow down or stop, if necessary, and give the right-of-way to crossing or merging vehicles. Yield the right-of-way to any cross traffic that is close enough to cause conflict.

When parking downhill, turn your front wheels into the curb or toward the side of the road. Set the parking brake.

You may not know what is on the other side of a hill or just around a curve, even if you have driven the road many times. If a vehicle is stalled just out of sight on the roadway, you must be able to stop. Whenever you come to a hill or curve, adjust your speed so you can stop if necessary.

You must turn on your headlights any time conditions prevent you from seeing other vehicles. Other drivers may have trouble seeing you, too.

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.

This sign warns that there is a flag person ahead. Always follow directions given by a flagger. Flaggers normally wear orange or yellow vests, yellow-green shirts, or bright jackets. They use paddles and red flags to direct traffic through the work zone and to let workers or construction vehicles cross the road.

Children who are eight years old or older, or who have reached at least 4 feet 9 inches in height, may use a properly secured safety belt meeting federal standards. Other children must be seated in a child passenger restraint system.