It may not look like cars change much on the outside from year to year, but crash testing is proving otherwise.

In testing by the Insurance Institute for Highway Safety, 37 cars, minivans and SUVs recieved the agency's Top Safety Pick award for 2008, a nearly three-fold increase from 2007's 13.

For automakers to win the Top Safety Pick award, a vehicle must earn the highest rating of good in the Institute's front, side and rear tests, and be equipped with electronic stability control (ESC). As automakers introduce new models or make safety changes to existing ones, the Institute adds winners throughout the year.

"When we first started doing frontal crash tests, automakers that didn't get a good rating complained that it wasn't accurate of what happened in a real crash, but they all figured out how to design their cars to get good ratings," said Russ Rader, the director of media relations at the IIHS. "Cars that get good ratings in our tests and five stars in government tests, people in those vehicles fare much better than those that aren't."

The latest Top Safety Pick award winner is the redesigned 2009 Subaru Forester, a small SUV. The IIHS said the award is intended to drive continued safety improvements such as top crash test ratings and the rapid addition of electronic stability control, which is standard on the Forester.

"Recognizing vehicles at the head of the class for safety helps consumers distinguish the best overall choices without having to sort through multiple test results," said IIHS president Adrian Lund.

"The performance of the Forester underscores Subaru's commitment to delivering state-of-the-art safety to its customers," Lund saof. "You don't know what kind of crash you're going to be in. That's why it's important to choose a vehicle that will protect you in all kinds of crashes. The Top Safety Pick designation is intended to help people find the safest choices."

The category with the most award winners is the midsize SUV, which boasts 17 of the 37 Top Safety Pick vehicles.

"More good news is that manufacturers have been moving quickly to add safety features like stability control and side airbags to their SUV models," IIHS senior vice president Joe Nolan said. "All of the SUVs in this group have ESC, and all but the [Jeep] Wrangler have standard side airbags. Increasingly, consumers are getting the latest safety equipment without having to hunt through a list of options."

In 2001 only half of the midsize SUV models that were tested earned good ratings in the frontal offset test. In the latest evaluations, all but the Hummer H3 do, and it earns an acceptable rating.

ESC is a control system comprised of sensors and a microcomputer that continuously monitors how well a vehicle responds to a driver's steering input and selectively applies brakes and modulates engine power to keep the vehicle traveling along the path indicated by the steering wheel position.

IIHS research indicates that ESC reduces the risk of fatal single-vehicle crashes by 56 percent and fatal multiple-vehicle crashes by 32 percent. Many single-vehicle crashes involve rolling over, and this feature reduces the risk of fatal single-vehicle rollovers by 80 percent in SUVs and 77 percent in cars.

The following cars were designated as Top Safety Pick award winners by the IIHS:

Large cars

• Audi A6
• Cadillac CTS
• Ford Taurus with optional electronic stability control
• Mercury Sable with optional electronic stability control
• Volvo S80

Midsize cars

• Audi A3
• Audi A4
• Honda Accord 4-door models
• Saab 9-3
• Subaru Legacy with optional electronic stability control

Midsize convertibles

• Saab 9-3
• Volvo C70

Small car

• Subaru Impreza with optional electronic stability control

Minivans

• Honda Odyssey
• Hyundai Entourage
• Kia Sedona

Midsize SUVs

• Acura MDX
• Acura RDX
• BMW X3
• BMW X5
• Ford Edge
• Ford Taurus X
• Honda Pilot
• Hyundai Santa Fe
• Hyundai Veracruz built after August 2007
• Infiniti EX35
• Lincoln MKX
• Mercedes M class
• Nissan Murano
• Saturn VUE built after December 2007
• Subaru Tribeca
• Toyota Highlander
• Volvo XC90

Small SUVs

• Honda CR-V
• Honda Element
• Subaru Forester 2009 models

Large pickup

• Toyota Tundra