You might be surprised to know that when it comes to governmentally mandated crash testing, things aren't as equal or representative of all passengers as you might hope. Specifically, I mean that the size, weight and design of crash test dummies often leaves engineers and scientists to make educated guesses on the effects of a crash on different body types and sizes.
The folks who do crash testing for the US government -- the National Highway Traffic Safety Administration -- are working on updating their methods to reflect actual people more accurately. The latest instance of this involves including a new toddler dummy designed specifically for side-impact crash testing with child seats.
Also new from NHTSA are some changes proposed to the Federal Motor Vehicle Safety Standard (FMVSS 213) that govern frontal crash testing for child restraints. Specifically, the agency suggests changing the labels on car seats to encourage parents to leave children in rear-facing child seats until they outgrow them in both size and weight. This has to do with the way safety systems such as airbags work in modern cars and potential injuries that could result from airbag deployments in a crash.
NHTSA is asking for public comments on the proposed changes, and instructions for leaving comments can be found here.