The end of the rear-end collision?

Seat belts and air bags go a long way to protect you and your passengers in a car crash, but new technology can prevent some accidents entirely and reduce the severity of others.

Volvo's collision-avoidance feature, called City Safety, is designed to prevent rear-end collisions in slow-moving, dense traffic. City Safety automatically brakes the car to avoid a rear-end collision when you travel at speeds between 2 and 19 mph. It uses a sensor built into the windshield to detect and react to other vehicles within 18 feet of the front bumper.

 The Highway Loss Data Institute (HLDI) gives City Safety high marks. HLDI is studying crash-avoidance systems on a variety of cars to determine which technologies are the most effective for various types of car accidents.

Get free custom rate quotes online, now.

"Our initial study of the Volvo City Safety technology shows that it significantly reduces the risk of rear-end crashes," says Matthew Moore, vice president of HLDI.

Crash-avoidance technology

City Safety is a standard feature on the following models:

• 2010, 2011 and 2012 Volvo XC60 midsize SUV
• 2011 and 2012 S60 sedans
• 2012 S80 sedans and XC70 wagons

The HLDI study compared insurance claims for the Volvo XC60 with car insurance claims for other Volvo models and midsize luxury SUVs from other manufacturers. It found that cars with City Safety were far less likely to be involved in low-speed crashes than cars without the system.

"We found that this model of the Volvo had 22 percent fewer collision claims, 27 percent fewer property damage liability claims and 51 percent fewer bodily injury claims," says Moore.

Similar results occurred when comparing the Volvo XC60 with other Volvos without City Safety.

Moore says Subaru has developed a system called EyeSight that provides a function similar to City Safety, but EyeSight is available only in Japan. EyeSight will be introduced later in 2011 on Subarus sold in Australia.

Car manufacturers have introduced many other crash-avoidance technologies. The HLDI says most new cars have antilock brakes and electronic stability control, which uses sensors and a microcomputer to automatically brake and modulate engine power to keep the car on the path indicated by the driver's steering wheel position.

According to HLDI, new crash-avoidance features in addition to antilock brakes and electronic stability control include:

• Forward collision warning and mitigation systems. Alert you when you are driving too close to the car in front of you. Some systems also brake your car.
• Adaptive cruise control. Allows you to set your speed to slow down in heavy traffic on the highway
• Pedestrian detection systems. Use cameras and sensors to alert you when a pedestrian is in the path of your car or about to enter the path.
• Lane-departure warning and prevention systems. Use cameras and sensors to alert you if you are straying over lane markers
• Side-view-assist sensors. Help you see what's in your blind spot
• Park assistance and back-over prevention systems. Help you avoid running over something behind you
• Adaptive headlights. Help you see around a curve at night
• Curve speed warning systems. Alert you if you are approaching a curve at an unsafe speed.

Moore says Volvo is committed to making City Safety available on all its vehicles in the future. However, he says there is no guarantee consumers will warm to the technology. Thus far, surveys by companies such as Volvo, Audi and Infiniti indicate that consumers of vehicles equipped with crash-avoidance technology like the feature.

"But those are purchasers who have deliberately bought a large, safe car," Moore says. "Customers who drive small sedans may feel like they are getting too many false warnings or that their car brakes too often."

Car insurance rates and crash avoidance

The pattern of results from the HLDI study shows that the frequency and severity of insurance claims is lower on cars with City Safety, Moore says. However, he is not sure this will necessarily translate into cheap auto insurance.

Michael Barry, a spokesperson for the Insurance Information Institute, says it is too early to assess the impact of the HLDI study on auto insurance, particularly since the study is based on just one car model.

"There is no doubt that as devices like City Safety become more common, there could be a very positive impact on insurance premiums," says Barry. "City Safety is particularly interesting because it addresses one of the most common types of accidents. This technology is a major leap forward in terms of crash-avoidance systems."

Barry says it may take insurance companies several years before they collect data on the effectiveness of specific crash-avoidance systems that will be conclusive enough to offer discounts for having a vehicle with this type of system.

"It's conceivable that we will see the day when there will be a standard discount for crash-avoidance systems similar to the discount you get for driving fewer miles than average, having an anti-theft device or taking a defensive-driving course," says Barry.