Three driving rules you need to remember

Rita Colorito

Driving rules exist to keep everyone safe. But if given the written test today, one in five drivers wouldn’t meet the basic requirements to get a driver's license, according to the 2011 GMAC Insurance National Driving Test. That’s nearly 37 million American drivers who don’t know basic rules of the road.

“People need to know the rules and execute the rules, but it doesn’t mean they will execute the rules,” says Scott Eckman, chief marketing officer at GMAC Insurance. “Most of what we see in accidents has to do with people’s unwillingness to follow the rules that they know. But we find it interesting that there is a significant portion of people who don’t know all the rules that they should know. So there’s a little bit of the chicken and the egg there.”

Drivers flunked the part of a nationwide driving test about flashing yellow traffic lights.

Here’s how to avoid three common driving mistakes -- and avoid an accident as well as higher car insurance costs.

1. You're not sure what to do at a flashing yellow light.

A flashing yellow traffic light stumped the most drivers in the seventh annual GMAC survey, with 85 percent not knowing what to do when approaching one. The answer: Slow down and carefully go through the intersection. The other two options were to stop totally, just like at a stop sign, or yield to all cross traffic before the intersection.

A flashing yellow light warns drivers of unexpected or hazardous conditions, such as a narrow bridge or a roadway obstructions.

Why does this matter? If a driver who guesses incorrectly stops at a blinking yellow light on a highway, the driver behind him -- going full speed -- might not stop and could end up  causing a rear-end collision. “It creates a dangerous environment,” Eckman says.

2. You're not safely following the car in front of you.

How many “one thousands” should you count to maintain a safe following distance behind the car in front of you? Three "one thousands," or the equivalent of three seconds. Only 27 percent of drivers got this question right on the GMAC test. The other possible answers were 10 seconds and 20 seconds.

“When you are following too closely, you physically don’t have the reaction time to avoid a mistake if the person in front of you does something, if they swerve to avoid something, if they slam on the brake. So (following too closely) is one of the significant causes of accidents,” Eckman says.

Rear-end collisions are the third leading cause of  car crashes, according to the National Highway Traffic Safety Administration. Using a driving simulator, researchers at the Georgia Institute of Technology found drivers aren’t able to detect when a car in front of them is going slower, putting them at risk for rear-enders. Researchers now are working on a collision warning system that will alert drivers to stop or slow down based on the speed of cars in front of them.

In the meantime, "add another second of following space for every additional hazard," says Pamela Cornell, who trains instructors at the Defensive Driving School in Bellevue, Wash. Those hazards include bad weather and road construction.

At 55 mph, it takes about 400 feet to react and bring your car to a complete stop, according to the California Department of Motor Vehicles. At 35 mph, it takes about 210 feet to react and bring your car to a full stop.

3. You're not thoroughly scanning the road.

Scanning the road wasn’t on the GMAC test but it is something experts like Eckman and Cornell say drivers don’t do properly. Most drivers focus only on the road immediately in front or behind them when they should be scanning the area surrounding them.

On familiar roads, some drivers really don’t scan their surroundings at all.

“We know these routes so well that we don’t pay attention," Cornell says. "We feel like we’ve seen it so much, we know where everything is already, and that’s when it becomes dangerous.”

According to the federal highway traffic agency, 52 percent of crashes occur within a five-mile radius of home.

“Scanning is the key to defensive driving. Things can come from any direction,” Eckman says.  “Someone else can be distracted and run a red light or a stop sign, or be approaching an intersection accelerating instead of decelerating. If you are only looking ahead or behind, you’re going to miss that side street.”

The California Department of Motor Vehicles advises drivers to look down the road 10 to 15 seconds ahead to spot hazards early.

“In the city, 10 to 15 seconds is one block. On the highway, 10 to 15 seconds is about a quarter of a mile," the Department of Motor Vehicles says.

And don’t rely on mirrors to notice hazards, Cornell says, as "there might be a vehicle beside you in your blind spot.”

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