This sign indicates that the overpass ahead has a low clearance. You should not proceed if your vehicle is taller than the height shown on the sign (in this case, 13 feet 6 inches).

Yield the right-of-way to snowplows engaged in work on the roads. Use extra caution in approaching, overtaking, or passing maintenance vehicles and snowplows. Because of their traveling speed and size, snowplows tend to create large clouds of blowing snow that conceal the plow, making it invisible.

Signs that are brown indicate areas of cultural and historical significance or of public recreation. They can be a helpful resource when traveling in unfamiliar locations.

You should always reduce your speed and use extra caution when children are in the vicinity. They may fail to understand the danger and may run out in front of you without looking.

Regulatory signs require drivers to obey an indicated instruction. Failure to comply is subject to penalty.

At dusk or on overcast days, you must turn on your headlights. Dim your lights to their low beam setting when within 1,000 feet of an approaching vehicle and when within 500 feet of a vehicle that you are following. When driving in poor weather, always use your low beams.

This sign indicates that there is a traffic signal ahead.

Warning signs prepare drivers for upcoming road conditions and hazards and are usually yellow with black markings. This sign warns drivers that they are approaching a winding road and that they should adjust their speed accordingly.

At intersections that are controlled by signs or signals and at intersections that are uncontrolled, the driver on the left must yield the right-of-way to the driver on the right when two vehicles arrive to the intersection at the same time.

A Pedestrian Hybrid Beacon (PHB) allows pedestrians to safely cross a roadway. A PHB only operates when activated by a pedestrian. When the PHB is displaying two solid red lights, you must stop for pedestrians.

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 must always yield to pedestrians who are in or about to enter a crosswalk. Be alert to pedestrians when driving across intersections or turning.

Massachusetts law requires that your headlights be on when you are driving in a tunnel. Headlights can help increase visibility in situations with normally lowered visibility.

As speed increases, the chance of a fatality increases. If you are moving faster than 80 miles per hour, you have almost no chance of living through a crash. Driving more slowly than other traffic can also be dangerous because other motorists may become impatient and make dangerous moves to pass you.

Yellow lines are used to divide traffic moving in opposite directions.

Check the traffic behind you several times a minute to know if another driver is tailgating, approaching too fast, or trying to pass. If another car is following you too closely, slow down and let it pass. Most rear-end collisions are caused by vehicles following too closely.

The distance that a vehicle needs to stop depends on the motorist's reaction time, weather and visibility conditions, the vehicle's weight, the conditions of the vehicle's brakes, the condition and type of the vehicle's tires, roadway conditions, and speed.

You cannot use any mobile electronic device to write, send, or read an electronic message while driving. This law includes text messages, emails, instant messages, or accessing the Internet.

When entering a freeway, use the on-ramp to accelerate to the speed of freeway traffic so you can blend in smoothly and safely. Entering traffic must yield to traffic already on the freeway.

It is illegal to drive so slowly that you disrupt the normal flow of traffic. You may receive a citation for driving too slowly.

A flashing yellow traffic light at an intersection indicates that drivers must slow down, proceed with caution, and be prepared to stop.

The ability to drive safely is dependent on the driver being in good physical condition. Driving can be impaired by alcohol, legal and illegal drugs, and being drowsy.

When exiting a highway, you should get into the exit lane well in advance. Do not begin to slow down until after you have moved into the exit lane.

It is estimated that drivers make 200 decisions for every mile traveled, making it vital that drivers focus their full attention on the task of driving. Performing any additional task can create a dangerous distraction.

If there are two railroad tracks next to each other, watch for a second approaching train after one train passes. Do not begin to cross the tracks until you’re sure no train is approaching from either direction on either track.