Measurements of human and dummy falling (often referred to as diving) speeds were made from four series of experiments. The first series consisted of a 5th and 50th percentile human and a 50th percentile dummy in a production vehicle with production belts, in a spit test at roll rates to 200 degrees per second. The second series was conducted with surrogates in dynamic repeatable rollover test roof impacts in the Jordan Rollover System (JRS) fixture. The third series photo analyzed dummy motion in the interior of dolly rollover tests with belted and unbelted hybrid III dummies to determine independently, the excursion and intrusion speeds of the dummy and roof. The fourth series analyzed Malibu rollcaged and production vehicle occupant belt loop load vs neck impact force similar to a previous analysis of Autoliv rollover tests.

The first series measured the near and far side lateral and vertical excursion, excursion speed, roll rate, and belt loads, as well as, documenting occupant kinematics by lateral and frontal view video cameras. The second series measured the near and far side excursion and excursion velocity of a belted surrogate in 15 mph, 350 degree per second JRS roof impact tests. The third series photo analyzed high resolution video of dolly rollover tests with 50% hybrid III dummies in addition to the parameters collected in the tests associated with roll rate, dummy head impact speed and belt loads. The fourth series analyzed Malibu roll caged and production belt loop load vs. neck impact force at roll rates up to 500 degrees per second.

The measurements are presented in a graphical format with discussion in the context of rollover injury potential. The conclusions are that belted humans and dummies with 3 to 5 inches of excursion, have excursion speeds of little more than 0.5 mph. The unbelted dummies with a similar amount of initial headroom have only slightly greater falling speed because of the short duration of the roof contact acceleration. Photo analysis of dolly rollover head impact speeds as measured by dummy neck loads, separated the excursion and roof intrusion speeds and indicated similar falling speeds. An inch or more of intrusion from a roll caged roof in combination with the close proximity of the head of a dummy result in composite head impact speeds of 3 mph or more.