Concrete barriers were found to have a significantly increased
propensity for airbag deployment compared to other metal beam or
cable barriers. Based on the weighted data, the airbag deployment
rates were 72% for concrete barriers compared to 61% for other
longitudinal barriers. Concrete barriers are more rigid than the metal
beam and cable barriers typically classified as“other barriers” in
NASS/CDS. These deployment differences are also consistent with
the limited amount of longitudinal barrier crash testing conducted
with the airbag systems activated.Grzebieta et al. (2002, 2005)found
that concrete barriers caused airbag deployment for all high speed
impact conditions investigated while only one of the two impact tests
with w-beam barrier resulted in airbag deployment.
Fig. 2shows that the probability of airbag deployment in longitudinal barrier collisions increased with increasing equivalent barrier
speed. Based on the available data, it appears that airbag deployment
occurs in all barrier collisions with an equivalent barrier speed greater
than 35 km/hr (21 mph). Approximately 83% of occupants exposed to
a tow-away longitudinal barrier collision were in vehicles where the
equivalent barrier speed was at or below 24 km/hr (15 mph).