No one number is safe in every situation. Choose your speed based on the weather, the road surface, how far you can see and how heavy traffic is, and remember that driving under the limit can still be too fast in poor conditions.
A siren or flashing red or blue lights mean an emergency vehicle needs the road. Move to the right edge, stop, and stay there until it has gone by; failing to do so breaks the law and puts lives at risk.
When a crash cannot be avoided, the goal is to reduce the force of the impact. Something that yields absorbs energy better than a rigid object, a stationary object is less violent to hit than an oncoming vehicle, and a glancing contact is far less dangerous than a direct, head-on hit.
The law requires headlights starting 30 minutes after the sun sets and ending 30 minutes before it rises, which means that in the morning you can turn them off when sunrise is half an hour away. Leave them on longer when rain, fog, or snow limits visibility.
Headlights are required from half an hour after sunset until half an hour before sunrise, plus whenever rain, fog, snow, or dim light makes people and vehicles hard to see. They help you see the road and help others see you.
Water on the pavement makes stopping take longer, so open up a gap of at least 4 to 5 seconds behind the vehicle ahead. Brake, steer and accelerate gently to avoid skidding.
Tip On wet pavement, plan on about twice your usual following distance so you have room to stop.
Before you back up, change lanes or brake suddenly, check the traffic behind you with your mirrors and by turning your head. Look over your shoulder through the rear window when backing, and check your blind spot before moving into another lane. These are the moments when a collision with someone behind you is most likely: backing takes you toward whatever is back there, and if you change lanes or brake hard, a vehicle coming up behind you may have no room to avoid you.
Highway traffic moves fast, so situations change in seconds. Paying full attention, scanning constantly, and being ready for hazards such as debris, stalled cars, or sudden braking all help you avoid a crash.
New Hampshire has no single school-zone number: in a signed school zone, drivers must slow to 10 mph below the normal limit during the set periods around the start and end of the school day. The lower speed leaves extra room to brake for a child who darts out.
When wipers quit during rain or snow, your view is nearly gone. Slow down, and if looking out the open driver's window is your only means of seeing ahead, do so; brake and leave the road at the first safe chance. Once stopped, put on your hazard flashers and wait until the weather clears or the wipers are repaired.
Your turn signal warns other drivers, your mirrors show traffic behind and beside you, and a quick look over your shoulder covers the blind spots the mirrors cannot reach. Skipping either check can leave a vehicle right beside you unnoticed, and skipping the signal leaves other drivers unaware that you are moving over.
To indicate a right turn, stick your left arm through the driver's window and bend it up at the elbow so your hand points toward the sky. A straight, extended arm signals a left turn, while an arm bent downward signals that you are slowing down or stopping.
Tight or curving roads, intersections, railroad crossings, and wet or slippery pavement all leave less room for error. A lower speed buys you reaction time and cuts the distance you need to stop.
The usual guideline is the three-second rule: keep at least 3 seconds between you and the vehicle ahead. In rain, fog or other poor conditions, leave more time so you can react and stop.
New Hampshire stands alone among the states in having no adult seat belt law. It does require every occupant under 18 to ride buckled up in a seat belt or a child restraint, with approved safety seats for young children, and buckling up remains the safest choice at any age.
Slippery pavement gives your tires less traction, so lose speed before a curve or intersection rather than while you are in it. Speeding into a curve, or waiting until you are already descending a hill to downshift, makes a skid more likely.
Blinking your brake lights or turning on the hazard flashers lets the people behind you know early that traffic is stopping for a crash ahead, which gives them room to slow down. These signals warn of danger or an unexpected slowdown; they are not a way to thank another driver or something to use while reversing out of a parking spot.
Tip Hazard flashers are for warning others of a sudden danger, not for excusing double-parking or for ordinary driving.
A stop sign, a red signal, and a stop order from an officer directing traffic each require a full stop. The same duty applies in other cases too, such as a school bus with flashing red lights or a train approaching a railroad crossing.
A U-turn in a school zone is dangerous because children may appear anywhere, and some states ban it there outright. Obeying the speed limit and letting children cross are duties in a school zone, not things to avoid.
At an intersection with no signs or signals, you yield to a vehicle approaching from your right, and a driver turning left yields to vehicles coming straight from the other direction. The yellow car has no one on its right, so it goes first; the blue car, which has the yellow car on its right, goes next; and the truck, turning left, goes last.
Set the front wheels so that the curb would stop the car if it started to roll: angle them toward the curb if the car points downhill and away from it if the car points uphill. Apply the parking brake every time.
Tip Downhill means wheels toward the curb; uphill with a curb means wheels away from it.
Cutting across a parking lot, gas station, or other property to avoid a sign or signal is illegal. The only exception is when a police officer directs traffic that way.
Emergency vehicles may stop or turn without warning, and others may be following, so the law requires you to stay back at least 500 feet once one has passed. Trailing it closely is dangerous, and after it goes by you may resume normal driving while keeping that distance.
Total stopping distance is the ground you cover while reacting plus the distance needed to brake, which depends on speed, brakes, tires, and the road surface. Darkness can make hazards harder to spot, but the clock itself does not change how far the vehicle needs to stop.
Tip When judging how quickly you can stop, think about speed, reaction time, brakes, tires, and pavement, not the hour.
After a blowout, hold the steering wheel firmly, take your foot off the accelerator, and keep the car going straight while it loses speed on its own. Braking hard can make you lose control, so stop only after you have eased off the road to a safe spot.
Passing must always be done on the paved, main part of the road. Pulling onto the shoulder or dirt edge to get by is never allowed, even next to a vehicle that is turning left.
Most states require a parallel-parked car to have its wheels within 12 inches of the curb, and some allow up to 18, so staying within 12 inches keeps you legal in either case. A wider gap leaves the car sticking out into the travel lane, where it becomes a hazard to passing traffic.
Tip A gap of roughly 6 to 12 inches keeps you within the limit while protecting your tires from the curb.
The headlight requirement begins 30 minutes after sunset, when fading daylight makes it harder for others to see you. Also turn them on at any hour when rain, snow, or fog limits visibility.
If a school bus stops on a two-lane road with its red lights flashing, traffic approaching from either direction has to stop and stay put until the lights go off and the bus moves on. Simply slowing down is not sufficient, including when the bus is on the opposite side of the road.
Tip Drivers on the far side of a highway split by a physical divider, such as a raised median, are not required to stop.
A school bus stopped with its red lights flashing is letting children on or off, and they may walk across in front of traffic. You must halt at least 25 feet away and stay there until the red lights turn off and the stop arm retracts.
Every question in this set has its own page with the correct answer and an explanation.
