Shining a Light on Defensive Driving

When the lights went out in Chico, Calif., last week, H. Thomas Ganz quickly pulled to the side of the road, parked and started watching.

Ganz had more than passing curiosity. The former California Highway Patrol officer now makes his living analyzing crash scenes as an accident reconstruction specialist.

And with the traffic signals out at three consecutive intersections on State Route 32, thanks to California’s new era of rolling blackouts, Ganz figured it was just a matter of time until he’d have some new observations for his notebook.

In 1999, the last year for which figures have been compiled, there was a traffic accident reported every 65 seconds somewhere in California, according to CHP records. That’s nearly half a million accidents.

In fact, Southern California has two of the most dangerous intersections in the nation: Brookhurst Street and Adams Avenue in Huntington Beach and Wilshire and Santa Monica boulevards in Beverly Hills. State Farm Insurance estimates that each was the site of more than 230 accidents in 1998.

If 2001 is the year of rolling blackouts, statewide accident figures could climb. Experts such as Ganz say there is no better time to shift into defensive-driving mode.

Technology promises to make defensive driving easier as features such as collision-warning systems, under study by most vehicle manufacturers, become available. But until your car or truck gets smarter, just knowing what the most common types of accidents are can help you adjust your driving habits to avoid them.

Most urban traffic accidents fall into five categories, according to a study conducted by the nonprofit Insurance Institute for Highway Safety in 1995.

Front- and side-impact crashes caused by drivers who run red lights or violate traffic controls such as stop signs lead the list. Then come rear-end collisions--usually caused by following too closely--and running off the road and striking an object, a type of accident that also is the leading cause of vehicle rollovers. The fourth-most frequent type of accident, the institute reported, are those caused when a motorist suddenly swerves into an adjacent lane. Fifth on the list are accidents resulting from improper left turns.

In California, according to the CHP’s 1999 tally, the most common causes of collisions are excessive speed, right-of-way violations, improper turning (a broad category that includes swerving into another lane), signal and stop sign violations, and driving under the influence of drugs or alcohol.

Drivers’ lack of attention is to blame for many if not most accidents. Indeed, Ganz said he saw three near-misses in the first minute after the blackout in Chico last week because drivers “at first were just going on through the lights” as if they were green in all directions.

But after a few minutes, motorists had become aware of the darkened signals and reacted properly, as if they were at a four-way intersection with stop signs.

As Ganz was observing the scene unfold up north, the same scenario was being played out in Southern California, with rolling blackouts affecting a number of traffic signals and contributing to the day’s accident tally.

The lesson? To avoid a crash at an inoperable light, drivers must react quickly. So concentrate on looking farther ahead than you typically do.

“People watch brake lights more than traffic lights,” Ganz said. Ideally, drivers should be aware of what’s going on six vehicles or more ahead of them, meaning they should be looking past the tail end of the car immediately in front.

“A lot of drivers don’t look forward enough,” agreed Luis Mendoza, a spokesman for the CHP’s Southern Division. But paying attention is more important than ever, he said. It can provide more time to react should a traffic light suddenly dim.

Other rules for safer driving are equally simple--and often ignored.

To avoid running red lights when the power is working, be aware that, although signal timing varies from community to community, a typical yellow “caution” light is on for 2.5 to 3 seconds between the green and red lights. That’s not a lot of time to make it though an intersection. So, in general, Ganz said, it’s better to stop, even if you risk being hit from the rear, than to race through the yellow light and be “T-boned” by a car speeding into the intersection from the left or right.

The best way to reduce the risk of being the cause of a rear-end collision is to keep your eyes on the road and maintain proper spacing between cars. That seems all too obvious, but Ganz said most people who rear-end other vehicles are either following too closely or are briefly inattentive as they look down to fiddle with the car radio or turn to admonish a child.

It might take only two seconds to look from the road to the radio, but at 30 miles an hour, a vehicle travels five or six car lengths in that time.

Run-off-the-road crashes are usually single-car accidents, most often caused by inattention, sleepiness, excessive speed or a combination, Ganz said.

Swerving into another lane, another leading cause of collisions, is often caused by a lack of attention, but it also can be caused by drivers who rely solely on side and rear-view mirrors. By looking toward the side--the “blind spot”--before changing lanes, a driver sees areas that the mirrors miss.

And most left-turn crashes occur because drivers misjudge how fast oncoming traffic is approaching, Ganz said.

One promising technology that may make defensive driving easier is adaptive cruise control, already available in the U.S. as an option on the Lexus LS 430 sedan and soon to be available on some Mercedes-Benz, BMW and Jaguar models.

Adaptive cruise control maintains a preset speed, just like a regular system, but uses sensors to adjust the speed to maintain proper distance from the vehicle ahead.

On the horizon are forward collision-warning systems, under study by all the major vehicle manufacturers, said James R. Sayer, an assistant research scientist at the University of Michigan Transportation Research Institute.

These work by using a sensor on the front of the car to detect other vehicles in your path and to calculate how quickly your car is closing the gap. If too quickly, the system sounds a warning.

And so-called road departure warning systems, already used by some commercial truck drivers, could help drivers of passenger vehicles too, said Dave LeBlanc, another University of Michigan transportation researcher. A camera linked to sophisticated software scans beneath the vehicle and triggers a signal if it detects the vehicle drifting over lane lines or off the edge of the road.

But no matter how sophisticated defensive-driving systems become, safety experts stress that accident reduction begins and ends with an attentive driver.

Said the CHP’s Mendoza: “Keep your eyes on the road.”

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Highway 1 contributor Kathleen Doheny can be reached at kdoheny@compuserve.com.

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Crunch Time

Most urban traffic accidents are caused--or exacerbated--by driver inattention. The seemingly simple acts of keeping one’s mind on the driving and one’s eyes on the road would go a long way toward cutting the national accident rate, experts say.

What happens on the road ...

The top five types of urban accidents in the U.S.:

1. Running a red light or violating other traffic controls such as stop and yield signs

2. Rear-end collisions, usually caused by following too closely

3. Running off the road and striking an object, often the cause of rollover accidents

4. Swerving into another lane

5. Turning left and colliding with an approaching vehicle

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... and the reasons why

The five most common causes of traffic collisions in California, according to the Highway Patrol:

1. Excessive speed

2. Right-of-way violations

3. Improper turning (swerving into the adjacent lane, for example)

4. Stop sign or traffic signal violations

5. Driving under the influence of drugs or alcohol

Source: Insurance Institute for Highway Safety

Rating the Risks: Single-Vehicle Rollovers

New rollover ratings developed by the National Highway Traffic Safety Administration are controversial because they depend on a mathematical model rather than on actual testing. But so far, they are the only thing the consumer can use when shopping for a new vehicle. Most rollovers are single-vehicle crashes that happen when a car runs off the road and is “tripped” by a ditch, curb, soft soil or other object. NHTSA says such crashes, which claim more than 10,000 lives each year, are usually caused by driver error, such as speeding or inattention.

The “rollover resistance rating” estimates the risk of rolling over in a single-vehicle crash. Essentially, it measures and compares the vehicle’s center of gravity and track width to determine how top-heavy a vehicle is. The most top-heavy, mainly tall pickups and sport-utility vehicles, are considered the most likely to roll over. To date, 70 vehicles have been rated:

5 stars: Less than 10% chance of rollover

Brand: Model

Ford Ford: Crown Victoria

Honda: Accord 4-door

Lincoln: LS

Mercury: Grand Marquis

Toyota: Camry 4-door

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4 stars: 10% to 20% chance of rollover

Brand: Model

Chevrolet: Prizm 4-door; Cavalier 4-door; Impala 4-door; Silverado pickup, extended cab, 2wd

Chrysler: PT Cruiser

Ford: Focus 4-door; Taurus; Windstar minivan

GMC: Sierra pickup, extended cab, 2wd

Honda: Civic 4-door; Odyssey minivan

Hyundai: Accent

Mercury: Sable; Villager minivan

Nissan: Quest minivan

Oldsmobile: Alero

Pontiac: Sunfire 4-door; Grand Am

Toyota: Corolla 4-door; Sienna minivan

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3 stars 20% to 30% chance of rollover

Brand: Model

Chevrolet: Suburban, 4wd; Tahoe, 4wd; Tracker SUV, 2wd; Tracker SUV, 4wd; S-10 extended cab pickup, 2wd; S-10 extended cab pickup, 4wd; Silverado regular cab pickup, 4wd

Ford: Escape SUV, 2wd; Escape SUV, 4wd

GMC: Sonoma extended cab pickup, 2wd; Sonoma extended cab pickup, 4wd; Sierra extended cab pickup, 4wd; Yukon, 4wd; Yukon XL, 4wd

Honda: CR-V 4-door SUV 2wd; Passport SUV, 2wd

Isuzu: Rodeo 4-door SUV, 2wd

Mazda: Tribute SUV, 2wd; Tribute SUV, 4wd, MPV minivan

Nissan: Frontier crew cab pickup, 4wd

Subaru: Forester

Suzuki: Vitara 4-door SUV, 2wd; Vitara 4-door SUV, 4wd

Jeep: Wrangler

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2 stars 30% to 40% chance of rollover

Brand: Model

Chevrolet: Blazer 4-door SUV, 4wd

Ford: Expedition, 2wd; Expedition, 4wd; Explorer 4-door, 2wd; Explorer 4-door, 4wd; F-150 regular cab pickup, 4wd

GMC: Jimmy 4-door SUV, 4wd

Infiniti: QX4 SUV, 2wd

Jeep: Grand Cherokee, 2wd; Grand Cherokee, 4wd

Lincoln: Navigator, 2wd

Mercury: Mountaineer SUV, 2wd; Mountaineer SUV, 4wd

Mitsubishi: Montero Sport SUV, 2wd; Montero Sport SUV, 4wd

Nissan: Pathfinder SUV, 2wd; Xterra SUV, 4wd

Oldsmobile: Bravada SUV, 4wd

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1 star Greater than 40% chance of rollover

Brand: Model

Chevrolet: Blazer 4-door SUV, 2wd

GMC: Jimmy 4-door SUV, 2wd

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Federal regulators determine a vehicle’s propensity to roll over in a single-vehicle crash with the static stability factor formula: one-half the tire-track width (T) divided by the height of the center of gravity (H). A score of 1.45 or more earns a five-star rating, while 1.04 or less gets a single-star rating.

Source: National Highway Traffic Safety Administration