Defensive driving basics

The idea behind it

You can't control what other drivers do. You can control how much warning you get and how many options you have when something goes wrong. Defensive driving is about keeping both as large as possible. That means looking far enough ahead to see trouble early, leaving enough space to react, and making sure other people can see you and guess what you'll do next.

Scan ahead and around

New drivers tend to stare at the road just past the hood. Experienced drivers look much further ahead, often 10 to 15 seconds of travel in town and more on the highway, then bring their eyes back to check closer in. A good scan pattern looks something like this:

• Far ahead. Brake lights several cars up, traffic signals about to change, a truck signaling to merge.
• Near ahead. The car in front, people stepping off the curb, a ball rolling into the street.
• Mirrors. A glance every several seconds, and always before you slow down, change lanes or turn.
• Sides. Driveways, parked cars with someone inside, cross streets and bike lanes.

Keep your eyes moving. Fixing your gaze on one thing, even an interesting one, is how hazards slip in from the edges.

Keep a cushion of space

Space is the thing that turns a close call into a non-event. Leave a gap of at least three seconds behind the car ahead in good conditions and more when conditions are worse. The following distance guide shows how to count it.

Space to the sides matters too. Avoid driving alongside other cars for long stretches, especially in a truck's blind spot. When someone tailgates you, ease off a little and let them pass. Speeding up only makes it worse. The extra space in front of you makes up for the lack of it behind.

When you stop behind another car, leave enough room to see its rear tires touching the road. That gap lets you pull around it if it stalls, and it keeps you from being pushed into it if you're hit from behind.

Make yourself easy to see and read

• Signal early, before you start braking or moving over, so others have time to react.
• Use your headlights in rain, at dusk and whenever visibility drops. Many states require them when your wipers are on.
• Stay out of other drivers' blind spots. If you can't see a truck driver's face in their mirror, they probably can't see you.
• Make eye contact with pedestrians and drivers at intersections when you can. Don't assume a wave means the way is clear behind them.

Read other road users

Watch for clues about what others are about to do. A car drifting within its lane may have a distracted driver. Front wheels turning on a parked car mean it's about to pull out. A driver who keeps changing lanes will probably cut in again. Cyclists and motorcyclists can be hidden by other vehicles and may move suddenly to avoid a pothole. Give all of them extra room.

At intersections, look left, right and left again before you go, even on a green light. Someone running a red light is hard to predict and easy to miss if you only look ahead.

Always have a way out

A defensive driver keeps asking a simple question: if the car ahead stopped suddenly right now, where would I go? The answer might be the shoulder, an empty lane beside you, or simply the space you left in front. If the answer is nowhere, change something. Drop back, move lanes or slow down until you have an option.

Manage yourself

Defensive driving also means being honest about your own state. Tired, upset, rushed or impaired drivers react slower and take more risks. Leave earlier so you don't feel pressed for time. Don't drive after drinking or using drugs that affect alertness, including some prescription and over-the-counter medicines. Read the label and ask a pharmacist if you're unsure. See drowsy driving and avoiding distraction.