A few quick taps on the brake pedal flash your brake lights and alert following traffic that you are about to slow down. That early warning gives those drivers time to react and helps prevent a rear-end crash.
Defensive drivers stay attentive and move their eyes constantly, watching the roadside and checking the mirrors every few seconds; staring straight ahead or counting on a last-second escape leaves you unprepared.
On dry pavement at highway speed, the minimum safe gap behind the vehicle ahead is 3 to 4 seconds; some states recommend a full 4. Leaving more room is fine, but only 2 seconds leaves too little time to react and stop.
The rule sets your following distance: when the vehicle ahead passes a fixed marker such as a sign, you should reach that marker no sooner than four seconds later. On dry pavement, that gap gives you time to notice a problem and stop.
Other drivers make mistakes, and open space around your car is what buys you the seconds needed to brake, steer, or otherwise avoid trouble.
Defensive drivers keep their eyes moving, looking well down the road and around the car so hazards are spotted early; fixing your gaze on the car just ahead or following only one car length behind leaves almost no time to react.
Looking at least 10 to 15 seconds down the road lets you notice trouble while there is still time to slow down or change lanes smoothly, instead of reacting abruptly at the last moment. Many handbooks advise looking even farther ahead, as much as 20 to 30 seconds.
Trouble can come from any direction, so open space ahead, behind, and to each side gives you time and room to react; avoid driving alongside other cars where they can box you in.
Turn signals, brake lights, headlights, and the horn all let other road users know what you intend to do. When they understand your plans early, they have time to respond, which helps everyone avoid collisions.
When traffic starts moving again on an upgrade, the car in front may roll back a little before it pulls forward, and the extra space keeps it from bumping into you.
You need a bigger gap when the pavement is wet or slippery, when visibility is poor, and when approaching vehicles are moving fast. A stop sign or your turn signal does not change how much time and room it takes to get across safely.
A quick blast of the horn is the fastest way to grab the other driver's attention so they can brake or steer clear. Waving or switching on your flashers is easy to miss in the few seconds you have.
Wet pavement gives your tires less grip, so stopping takes longer and needs more distance than on a dry road. A cushion of 5 or 6 seconds behind the vehicle ahead gives you room to brake smoothly and avoid a skid if it stops suddenly.
A smart lane position helps you see and be seen, stay out of other drivers' blind spots, avoid wind blast, keep an escape route open, and discourage others from squeezing into your lane.
In normal conditions, stay at least three seconds behind the vehicle ahead: when it passes a fixed object, you should be able to count three seconds before you reach the same spot. Leave even more room when the weather is bad or it is hard to see.
Constantly moving your eyes across the road and its edges lets you spot trouble early, giving you time to respond calmly to people, other vehicles or a change in conditions. Staring at one spot shrinks what you notice.
Brake lights turn on whenever you press the brake pedal, warning traffic behind you that you are losing speed or about to stop. Check them regularly, because a burned-out bulb leaves following drivers without that warning.
Looking far down the road lets you spot trouble early, and a safe gap behind the car ahead gives you room to slow down gradually. Together, these habits make sudden hard braking much less likely.
As the red zones in the picture show, a car's mirrors leave areas to each side and toward the rear uncovered; these blind spots can be checked only by turning your head to look.
Scanning left and right lets you spot cross traffic, pedestrians, and trains before you enter these areas. A full stop is not always required, and passing a vehicle that has stopped is dangerous because it may be waiting for a pedestrian you cannot see.
Tip Even on a green light, check left, then right, then left once more before you roll into an intersection.
Every question in this set has its own page with the correct answer and an explanation.
