An improvement.  

They tested.  They made an improvement.  Probably the first of many.

There's a post a few below this that quotes those involved and the specific changes they are making.

Maybe in addition to looking for ways to continue to improve car safety, they can look at making a rule (or rules) about the blatent, ill-advised blocking and the pushing (sometimes 2 & 3 cars back) that are the major cause of most of the wrecks.