Bull bars and vulnerable road users

Pedestrian injuries are a leading cause of the global death and injury burden, accounting for 65 percent of the 1.2 million annual road deaths. The purpose of this brief literature review is to examine whether bull bars, a rigid aftermarket accessory fitted to the front end of passenger vehicles, increase the risk of severe and fatal injuries to vulnerable road users in the event of a collision.

Applicable peer-reviewed research, review papers, and grey literature were identified from a search of MEDLINE; the Transportation Research Board (TRB) database composed of Transportation Research Information Services (TRIS) and International Transport Research Documentation (TRID) databases; the Cochrane Database of Systematic Reviews; and Google Scholar. The following search terms were used: "bull bars" OR "nudge bars" OR "sahara bars" AND "pedestrians" OR "vulnerable road users" for 1948 to March 1, 2011. A secondary set of search terms was also included "bull bars" OR "nudge bars" OR "sahara bars" OR "vehicle frontal protective systems" AND "pedestrians" OR "vulnerable road users" for 1948 to March 1, 2011.

Neither the MEDLINE search nor the Cochrane Review search returned any relevant literature. The TRID search returned 19 research articles, 9 of which were included. Searches using Google Scholar returned 110 items, of which 21 were included in the present review after excluding patents and citations. Seven of the articles from TRID were also found in the Google Scholar search, resulting in 23 unique articles being included in this review. The studies used included 12 real-world studies, 3 computer modeling studies, and 8 laboratory testing studies. Very few studies examined the road safety of pedal-cyclists and motorcyclists; therefore, we focused solely on studies examining pedestrian safety.

The literature reviewed in this study indicates that vehicles fitted with bull bars, particularly those without deformable padding, concentrate crash forces over a smaller area of vulnerable road users during collisions compared to vehicles not fitted with a bull bar. Rigid bull bars, such as those made from steel or aluminum, stiffen the front end of vehicles and interfere with the vital shock absorption systems designed in vehicle fronts. These devices therefore significantly alter the collision dynamics of vehicles, resulting in an increased risk of pedestrian injury and mortality in crashes. This literature review shows that bull bars do indeed increase the severity of injuries to vulnerable road users in the event of a collision and highlights the need for current traffic safety policies to reflect the safety concerns surrounding the use of bull bars.