ARLINGTON, Va. — The Insurance Institute for Highway Safety recently revealed that it picked two new Toyota vehicles as Top Safety Pick award winners. The two units are the all-new Sienna minivan and redesigned 2011 Avalon full-size sedan.

Toyota executives believe the Sienna is the first and currently the only minivan to earn an IIHS Top Safety Pick since the rollover test was added to the criteria.

IIHS officials explained the Top Safety Pick is the highest safety designation they give. To qualify, they emphasized a vehicle must earn the highest rating of "good" in the IIHS front, side, rollover and rear impact tests and be equipped with electronic stability control.

IIHS pointed out that testing was made more stringent this year with the addition of the rollover examination.

To earn a "good" rollover rating, officials indicated a roof must be able to support the equivalent of four times the vehicle's weight. They said the current federal standard of 1.5 times.

In the IIHS testing, officials reported the Sienna roof withstood a force equal to 4.12 times the vehicle weight. They added the Avalon's weight withstood 4.07 times the vehicle weight.

Toyota also stressed that all of its models meet or exceed the safety requirements of the federal government and the National Highway Traffic Safety Administration.

IIHS reiterated that it is an independent nonprofit research and communications organization funded by auto insurance companies.