In an automobile accident, passengers are two and a half times more likely to suffer a traumatic brain injury in a side-impact crash than in a head-on collision, according to a recent study at the University of Rochester.

After analyzing 1,115 accidents nationwide in that took place in 2000, researchers also discovered that not only is brain injury more likely in side-impact crashes, the injuries were more severe, according to an article in the Rochester Democrat and Chronicle.

“Your head is very close to the window or another object the car is striking. The door doesn’t absorb much energy,” said Jeffery J. Bazarian, an author of the study, which appeared in the Annals of Emergency Medicine Aug. 1.

The study suggests the auto industry install more side airbags that protect the head, pelvis and chest, rather than just the head. Structural vehicle changes ��� including side air bags ��� could prevent 2,230 fatal or critical brain injuries a year, according to the study.

According to the report, traumatic brain injury results in death in 51 percent to 74 percent of single-car side collisions, and in 41 percent to 64 percent of multiple car side-impact crashes.

“Manufacturers have done a really good job of protecting the front and the rear of the car, but the sides are naked,” Bazarian said. “If you can make the side of the car as safe as the front, you could prevent a lot of deaths and injuries.”

He also said side crashes also cause more injury than other crashes because of vehicle mismatch. “You have tank-like SUVs hitting smaller cars.”

By the 1999 model year, vehicles were federally required to have front driver and passenger airbags, but didn’t require side airbags. Twenty-one percent of 2004 vehicles offered side airbags as an option, which cost buyers an extra $400.

The federal government estimated that it would cost the auto industry $1 billion to make side airbags standard, but the O.S. Department of Transportation proposed that the government require more safety standards, including side airbags, to deal with side-impact crashes. The measure could become regulation next year.

The UP study’s crash numbers were put through a formula that took speed, seat belts and alcohol involvement into account.