Road traffic crashes are a major cause of traumatic brain injury (TBI),
particularly among vulnerable road users (VRUs). However, current injury
prevention strategies often overlook the heterogeneity of TBI—which include
various injury types and severities—leading to an oversimplified approach to
evaluating helmets and safety systems in regulations and ratings. To identify
priority TBI types and severities in VRUs and to inform targeted prevention
strategies, the German In-Depth Accident Study database was analyzed and a
pathoanatomic classification system, i.e., Abbreviated Injury Scale, was
employed. AIS 2 (moderate) TBIs account for 70-80% of all brain injuries across
VRU groups, nearly half of which are concussions. For helmeted cyclists, milder
TBIs are at a greater percentage than for unhelmeted cyclists. These findings
highlight the need for expanding prevention efforts to include AIS 2+ injuries.
Key injury types observed include concussion (with and without loss of
consciousness), skull base fracture, subdural hemorrhage, contusion and
laceration. New mechanism-specific injury criteria may be needed to address
these injuries. The strong similarity in injury type ranking among different
road users (the Kendall’s tau values ranged from 0.90 to 0.93) suggests similar
needs for injury prevention. A new brain injury assessment criterion may serve
all road user types.
