ARLINGTON, Va. (CNN) - Recent high-speed, front-end crash tests on three different models of both SUVs and sedans show that the vehicles in general are becoming safer, the Insurance Institute for Highway Safety said Wednesday.

"This is good news because it means vehicles are getting safer," IIHS President Brian O'Neill said of the results of the 40 mph frontal offset crash tests. "These new results provide further evidence that auto manufacturers are designing safer vehicles," he added.

The institute used a midsize 2003 Volvo XC90, a 2003 Honda Element and a 2003 Mitsubishi Outlander in the SUV testing, and a 2002 Acura RL, 2003 Cadillac CTS and 2003 Infiniti Q45 in the sedan tests. All three SUVs rated "good" overall in the crash tests and each got "best pick" designations from the IIHS.

The Cadillac CTS and Infiniti Q45 also got "good" ratings and were listed as "best picks," while the Acura RL got an "acceptable" rating. O'Neill said the tests ran the vehicles into a deformable barrier, comparable to the front end of another vehicle, at 40 mph.

"The tests simulated forces that can occur when one car strays across the center lane and hits another with the drivers' sides overlapping," he explained. "This is a very severe test."

O'Neill said when testing was begun several years ago, "most [vehicles] were failing miserably." But, he said, advances in vehicle design are now evident. "Without proper design, injuries in such crashes could be life-threatening," he said. "With the proper design, occupants in the vehicles can walk away without serious injury."

In the testing, evaluations were based on three performance aspects: measurements of occupant compartment intrusion, injury measures from a Hybrid III dummy positioned in the driver's seat, and analysis of a slow-motion film to see how well the vehicle's restraint system controlled the dummy's movement during the test.

The Acura RL's "acceptable" rating was based on the resulting damage to the occupant compartment. There was "more collapse of the occupant compartment than we like to see in the offset test, and intrusion into the footwell area contributed to the high forces on the dummy's right leg," O'Neill said, adding that the dummy's head also hit an interior pillar.