Defensive Driving: Preventing Crashes, Aggressive Driving and Road Rage, Distractions, Tired Drivers and Maggie's Law, Communicating, Following Distances, Changing Lanes, Wet Roads and Hydroplaning, Snow and Ice, Reduced Visibility, Night Driving, City and Highway Driving, Work Zones, Skids, Emergency Stops, Vehicle Failures and Crashes

Written for aiforu2 as the source for a practice-test bank and the on-device tutor for the New Jersey driver license knowledge test. The facts follow the official manual; the wording is ours.

Source: New Jersey Driver Manual (2025), New Jersey Motor Vehicle Commission (MVC), chapter 5 "Defensive Driving" (pp. 90–111).

Prevent a crash

Most crashes come from driver error. The formula: be alert (never assume the other driver will not err), be prepared (know what to do when you must act fast, expect the unexpected), and act in time (do not panic).

Aggressive driving and road rage

Cool off before driving when angry. Aggressive driving is a progression of unlawful acts: unexpected speed changes, improper or erratic lane changes, disregarding traffic control devices, failing to yield, and following too closely. Keep up with the flow, use mirrors and signals and stay centered when changing lanes, obey devices (a right on red only after a full stop and yielding), always yield, and never tailgate; use the three-seconds-plus rule. Extreme cases become road rage, with drivers running lights, speeding, tailgating, weaving, passing illegally on the right, gesturing, screaming, honking and flashing high beams. Report an aggressive driver by calling (888) SAF-ROAD or #77 from a cell phone, ideally after pulling over.

Distractions and tired drivers

Inattentive drivers tailgate, speed, drift and ignore signs. Never light a cigarette, fasten a belt, reach across the seat, dig for toll coins, adjust a watch or mirror, tend children or pets, remove a coat, read maps, eat, use a phone or other device, adjust the radio, apply makeup, shave or use a laptop while driving. A tired driver reacts slowly, gets upset easily and may fall asleep; a tired driver can be as dangerous as a drunk one. Maggie's Law (June 2003) makes knowingly driving while impaired by lack of sleep recklessness under the vehicular homicide law. Avoid highway hypnosis by not staring at one thing for more than a few seconds, resting every two hours and sharing the driving. Most at risk: the sleep-deprived, long drives without breaks, night driving, sedating medicines or alcohol, driving alone, long boring rural roads, young people, shift workers and commercial drivers.

Communicating and following distance

Use every signal: stay in the lane that shows your intention, use turn and hand signals, catch other drivers' eyes, tap the horn, and at night flick the headlights from low to high and back. Be patient in city traffic and avoid quick turns; turn on hazard flashers whenever you pull off the road.

Tailgating is a common cause of crashes and chain rear-end collisions. Keep space on all sides, stay mid-lane, and leave room ahead to stop or pass. Rule of thumb: one car length (about 20 feet) per 10 mph, more at high speed or in bad weather. The three-seconds-plus rule works at any speed: pick a fixed object, start counting when the vehicle ahead passes it, and if you reach it in under three seconds you are too close. Stopping distance is perception plus reaction plus braking distance; keeping a foot near the brake shortens reaction distance; heavier vehicles take longer; and in bad weather stretch the count to four seconds or more.

Changing lanes, passing and being passed

Do not straddle lanes. Look in the mirror, glance back at the blind spot and signal. Pass or change lanes only when necessary, only without speeding, only where signs and markings permit, keeping a safe following distance, checking ahead and behind, signaling every change and the return, returning only when the passed vehicle shows in your rearview mirror, and canceling the signal. When being passed, stay in your lane and slow down to make the pass easier, resuming speed once the other vehicle is well ahead.

Wet roads, hydroplaning, snow and ice

Drive slower on wet roads, stretch the three-second rule to four or more, and avoid quick turns or speed changes. Hydroplaning, tires riding on a film of water, begins at about 35 mph; above 55 mph tires may leave the road entirely, making braking virtually impossible and turning impossible, so a gust, a dip or a slight turn can start a skid. Avoid bald tires, slow in heavy rain, standing water and slush, and drive on the highest part of the road, such as the center lane of a multi-lane highway.

Winter brings darkness, fog, rain, snow, sleet and ice. Warm up the engine per the manufacturer, use proper washer fluid, and clear all snow and ice; you are liable for ice that flies off and causes death, injury or damage. Test the road by braking gently at low speed. A vehicle skids when you accelerate too quickly, turn too fast or brake improperly. With ABS keep a foot on the pedal and do not pump; with conventional brakes use firm steady pressure, and if the wheels lock, release and reapply with slightly less pressure, repeating with less and less until under control. Snow tires help in snow but not on ice; chains give the best traction on ice and deep or packed snow; studded tires are legal November 15 to April 1. Start on snow with low engine speed and a lower gear if the wheels spin, and rock between forward and reverse when stuck. Idling is limited to three consecutive minutes, with exceptions for traffic, repairs, inspection lines, emergencies and buses loading.

Reduced visibility and night driving

Rough, wet or snowy roads need longer following distances: on snow, six seconds or more. Scrape and wipe the windows and run the defroster; if it fails in freezing rain, stop safely and let the heater clear the glass. In fog slow down, use low beams and fog lights, and follow the markings and other vehicles' lights. Against sun glare, set the visor without blocking the road, grip the wheel and slow down. Whenever visibility drops badly, stop on the shoulder out of traffic with flashers on.

Nearly 90 percent of driving decisions depend on what you see, and night cuts vision, so slow down and never outdrive the headlights. With a nighttime reaction time of 1.5 seconds on low beams, stopping takes 75 feet at 20 mph, 135 at 30, 211 at 40, 302 at 50, 409 at 60 and 530 at 70. Use headlights at dusk, night, dawn, on dark days and whenever visibility is under 500 feet (and whenever the wipers run); drive slower than by day; watch for signs, unlit or slow vehicles, bicycles, pedestrians and animals; and allow bigger safety margins.

City, highway and hazard driving

In the city, cooperate, drive slower, and watch pedestrians and less visible bicycles, mopeds, motorcycles and wheelchairs, which always have the right-of-way in a crosswalk, marked or not. Look at least 12 seconds ahead, about a block at 25 mph. Check intersections ahead from mid-block, slow and glance left then right with your foot on the brake, and be at your slowest at the crosswalk. A wide, smooth or busy road is not protected: with no signals there is no traffic control. Look, listen, think. Highways invite relaxed attention and crashes happen even in good weather; stay alert and within the limit. Slow for hills, dips, narrow bridges, bumps and railroad tracks, since speeding and hard braking can cause a skid or spin, and slow until livestock or deer have passed.

Work zones double all traffic fines; an advance warning sign or flashing vehicle lights appear up to one-half mile before the work, flaggers may control traffic, detours or diversions may reroute you, and an End Road Work sign closes the zone. Nationwide there are nearly 800 fatal and over 37,000 serious injury crashes in work zones a year. Stay alert, obey signs and flaggers, turn on the headlights, do not tailgate, do not speed, minimize distractions, expect the unexpected and be patient.

Reacting to problems

Never turn the ignition to the lock position while moving, or the steering locks. Skids: sudden turns, lane changes or hard braking cause them, often on wet or icy roads; handle front- and rear-wheel drive the same way, ease off the gas, turn in the direction the rear is skidding without oversteering, look where you want to go, and straighten as control returns; avoid the brakes in a side skid. Emergency stops: on a paved shoulder, signal and pull off at or near traffic speed and then slow; on an unpaved shoulder, slow first; turn on parking or hazard lights, never stand behind the vehicle at night, put a flare just behind the car and another at least 300 feet (about 120 paces) back, raise the hood and tie a white cloth to the antenna or left door handle. Running off the pavement: do not steer back at once; stay on the shoulder, ease off the gas, and once under 25 mph turn the wheel one-quarter turn toward the road to climb the edge. Car fires (usually electrical shorts): get everyone out and away and call for help; never fight the fire. Plunging into water: a closed car floats three to ten minutes; wear the belt to survive the impact, escape through an open window while afloat (doors will not open against the pressure, power windows may short), a front-engine car sinks nose first with air near the rear roof, doors open once pressure equalizes, and follow the bubbles up. Stalling on tracks: get everyone out and away even with no train, call the number on the Emergency Notification sign or 911, and if a train is coming run at a 45-degree angle away from the tracks toward the train to avoid flying debris.

Vehicle failure

Brakes: shift to a lower gear and pump the pedal fast and hard; if that fails, apply the parking brake while holding its release so you can ease off if the rear wheels lock, and stop off the road. Blowout: hold the wheel firmly, keep straight, lift off the gas, do not brake, and coast to a safe spot. Power steering fails when the engine dies: grip harder and stop safely. Headlights out: stop off the road, try the switches, then use parking lights, flashers or signals and call for help. Stuck gas pedal: eyes on the road, shift to neutral, steer off the road and shut off the engine. Hood flies up: slow, look under the hood or out the side window, use the lines as a guide and pull off. Wipers fail: slow, pull off and use the flashers.

Crashes

If a hit looks likely you can stop, turn or speed up. To stop quickly, pump conventional brakes to keep steering; with ABS press hard without pumping. To turn, steer away and off the road if necessary, avoiding the brakes while turning and never braking hard onto a soft shoulder. Speed up when a vehicle is about to hit you from the side or behind and there is room ahead, then slow once clear. Last-minute choices: turn away from oncoming traffic even off the road; hit something that gives way (bushes) rather than something hard; hit something moving your way rather than stationary, and stationary rather than oncoming; make it a glancing blow, never head-on, since every inch off center dissipates energy. About to be hit from the rear, be ready to brake so you are not pushed into the car ahead, brace between wheel and seat and press your head against the headrest; from the side, grip the wheel tightly and be ready to steer if you spin; head on, shield your face with your arms if belted with air bags, otherwise throw yourself across the seat. Hitting a parked vehicle requires notifying police and trying to find the owner.

At any crash: stop, stay calm, assume the worst and get help, wait at the scene without blocking traffic, ask passersby for help and warn oncoming traffic. The law requires notifying police of crashes with injury, death or damage; do not move a body before police or an ambulance arrive. When damage exceeds $500 or someone is hurt, send a written report to the MVC within 10 days unless police file one, notify your insurer at once, and see a doctor if shaken.

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