Vehicle mass and injury risk in two-car crashes: A novel methodology

► We introduced a novel methodology to estimate the partial effects of mass, through the velocity change, on absolute driver injury risk in two-car collisions. ► The novel aspect of the methodology is in providing a solution to the issue of lack of data on the speed of vehicles prior to the crash as well as a solution to the issue of lack of information on non-injury two-car crashes in national accident data. ► In a two-car collision, vehicle mass has a protective effect on its own driver injury risk and an aggressive effect on the driver injury risk of the colliding vehicle. ► There is a protective effect of vehicle size above and beyond that of vehicle mass for frontal and front to side collisions.