A new study by the Insurance Institute for Highway Safety found that death rates in car-SUV crashes have fallen, according to a May 3 Wall Street Journal report.Statistics show that in collisions between SUVs and cars, the occupants of cars still are much more vulnerable than are those in SUVs. However, the IIHS study suggests the application of new technology and greater use of seat belts may help to mitigate this gap.In cars that collided with mid-weight SUVs, the death rate fell 39 percent from 2000 to 2003, to 42 deaths for each one million registered SUVs. A decade earlier, the rate was 69 deaths for each one million registered SUVs. The decline in the death rate was more pronounced in collisions involving heavier SUVs, from 86 deaths for each one million registered SUVs to 49.The Institute says basic safety measures explain the improvement during the past decade: better vehicle designs, increased use of seat belts and the fact that half of all registered cars now are equipped with driver air bags, compared with 3 percent in 1990, according to the Wall Street Journal report. SUVs also have changed over that time period, going from heavier, more aggressive truck underbodies to SUVs built on car frames that inflict less harm in a crash. Concern about the dangers light trucks pose to cars has increased as SUVs have proliferated on the roads. Last year, SUVs and light trucks accounted for 55 percent of new-car sales, up from 40 percent a decade ago.The Institute, the Arlington, Va., research arm of auto insurers, specifically looked at the differences in height and weight of vehicles and how that mismatch affects death rates in crashes. It found that while incompatibility still is an issue, it is less of a problem than it was a decade ago.While cars have gotten safer in crashes with SUVs, the safety of the SUVs has changed little, if at all. In crashes with cars, the death rates for people in both SUVs and pickup trucks generally improved only slightly. The death rates were slightly worse for the lightest and heaviest SUVs. Still, the death rates for occupants of SUVs is substantially lower than it is for car occupants when the two vehicles collide, and as the SUVs get heavier, they get safer for their own occupants but deadlier for the cars involved in the crash, according to the report.