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.
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.
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.
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.
Without a sign showing otherwise, residential districts carry a 25 mph limit. Homes along the street mean children, walkers and bike riders may appear suddenly, so keep your speed down and stay ready to brake.
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.
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.
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.
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.
Headlights are required for the whole period between sunset and sunrise, not just a short stretch at dusk or dawn, and also whenever rain, fog or other conditions make it hard to see. Your duty to use them does not depend on what other drivers are doing.
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.
Headphones covering both ears block out sirens, horns and other warning sounds, which is why driving with them on is prohibited in California and several other states. Adjusting mirrors while moving or letting a pet roam the car can be distracting, but neither is covered by that ban.
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.
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.
Every question in this set has its own page with the correct answer and an explanation.
