One situation where it is appropriate to use your horn is if you lose control of your vehicle. In this case, sound your horn to alert other drivers.

When you hear the siren of an emergency vehicle, you must pull over to the curb or side of the road and stop.

Drugs (including illegal, prescription, and over-the-counter medications) can affect your brain function and impair your ability to drive safely. Combining alcohol with other drugs will increase the risk of a crash.

If another driver is threatening you or intentionally driving dangerously around you, remain calm and try to put as much distance between the two of you as possible. Slow down and let them pass. Do not make eye contact and do not make obscene gestures.

Pedestrians should not enter a street or crosswalk when vehicles are approaching. Though pedestrians have the right-of-way in crosswalks, a vehicle approaching from a close distance may not have the time to stop before entering the crosswalk.

When there is more than one potential hazard on the road, you should ensure that you only have to deal with one of them at a time. For example, when there is a bicyclist on the right that you want to pass and an oncoming car to the left, you should not try to squeeze between both at the same time. Instead, let the oncoming car pass, and then pass the bicyclist.

To complete a turn safely, you should activate your turn signal three to four seconds before your turn.

Hydroplaning happens when a vehicle glides on top of a thin layer of water between its tires and the road. Tires with low air pressure or bad tread can increase the risk of hydroplaning. Speeding also increases the risk.

This sign indicates that the right lane on a multilane roadway ends ahead. Traffic in the right lane must merge left.

You cannot enter an intersection if traffic is backed up on the other side and you cannot get completely through the intersection. Wait until traffic ahead clears so you do not block the intersection.

Do not drive in someone else’s blind spot. Move forward or drop back so that the other driver can see you.

You may cross a single broken line to pass or change lanes as long as you can do so safely and without interfering with traffic.

A motorcycle is a full-size vehicle with the same privileges as any other vehicle on the roadway. You should allow a motorcyclist a full lane width. Although it may seem as though there is enough room in the traffic lane for a larger vehicle and a motorcycle, remember that the motorcycle needs room to maneuver safely.

Each time you pass another vehicle, there is an increased chance for a collision. If you are moving faster than surrounding traffic, you will have to continue passing others. Drive with the flow of traffic, within the legal speed limit, and pass only as needed.

Even the smallest amount of alcohol will reduce your concentration, perception, judgment and memory, and your driving skills will suffer. No one can drink and drive safely.

Massachusetts law requires that your headlights be on one half hour after sunset until one half hour before sunrise. Headlights can help increase visibility in situations with naturally lowered visibility.

If there is no stop line or crosswalk, you should stop at the point nearest to the intersecting roadway where you can get a view of approaching traffic. You should not enter the intersecting roadway to gain a better view.

You are required to use your headlights during the day when visibility is reduced to 500 feet or less. When you first turn on your headlights, be sure they are adjusted to the low beam setting. Using high beams in fog or rain will cause the light to reflect back into your eyes, lowering visibility even more.

Highway work zones are established according to the type of work underway along the roadway. Signs in work areas are typically diamond-shaped, orange, have black letters or symbols, and serve as a warning that people are working on or near the highway.

Crashes often happen because one driver does something that other road users are not expecting. You should communicate with other motorists, bicyclists, and pedestrians by doing things like signaling when slowing down, stopping, or changing direction. Use your emergency signals or horn when appropriate.

Directions given by traffic officers take precedence over signs, signals, and pavement markings. People authorized to direct traffic include police officers, fire police, highway work area flag persons, and school crossing persons.

A flashing yellow traffic light means drivers should slow down and proceed with caution.

This sign is used with a traffic signal to tell drivers that left-turning traffic does not have the right-of-way and must instead wait for oncoming traffic to clear.

Fluorescent yellow-green is used as background color for pedestrian, bicycle, and school warning signs. Use extra caution when driving around these signs.

You should slow down as you enter a curve and increase your speed gradually as you exit. Increasing your speed as you enter a curve will make it more difficult to control your vehicle.