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.
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.
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.
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.
Flashing red lights mean the bus is picking up or dropping off children, so traffic behind it must halt and remain stopped until the lights shut off and the stop arm retracts. Slowing down or passing instead is illegal and dangerous. How far back you must stop depends on the state; where the law gives a distance, it is usually 10 to 20 feet.
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.
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.
A school zone carries a 15 mph limit while the restriction is in effect, such as during school hours when children are around. Slow down and watch closely for students and crossing guards. Stop and wait whenever a crossing guard holds up a STOP sign or children are in the crosswalk.
When the wipers fail in rain or snow, ease off your speed at once, open the driver's window and look out of it if that is the only way to see, and then brake and leave the road at a safe spot. Wait there with your hazard flashers on until the weather clears or the wipers are fixed.
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.
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.
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.
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.
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.
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.
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.
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.
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.
The driver and every passenger, in the front and in the back, must be buckled up whenever the vehicle is moving, and young children like the one pictured must ride in a properly installed child safety seat. Seat belts sharply reduce the chance of serious injury or death in a crash.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
High speeds and heavy traffic on major highways leave little time to respond, so you need to stay focused, scan the road and mirrors continually, and be ready for hazards such as stalled vehicles, debris, or sudden slowdowns.
Every question in this set has its own page with the correct answer and an explanation.
