Toyota's RAV4 gets good marks for safety on most tests, but it received a "poor" score in a new type of crash test run by the Insurance Institute for Highway Safety. Toyota says it is working hard on improvements. Photo credit: Toyota.

A new kind of crash test has sent Toyota (NYSE:TM) engineers scrambling. The test, run by the Insurance Institute for Highway Safety, tests a common type of crash that's responsible for many serious injuries. It isn't yet part of the government's new-vehicle crash testing, but it could be in time -- though already, researchers think it's a big deal.

Several Toyotas did poorly on this particular test -- but well on other crash tests --  and in response the company told Automotive News this week that it's hard at work on safety improvements for several of its models. In this video, Fool contributor John Rosevear explains why the test is important -- and why Toyota's response is a positive sign for the giant Japanese automaker.