A bull bar is a rigid structure, usually metal (plastic bars also exist) which is fixed to the front of a vehicle and is designed to protect a vehicle against damage to items such as the radiator and headlights.
The Australian Design Rules (ADR) are design requirements for vehicles that set minimum standards for Safety, Emissions and Anti-Theft equipment. ‘ADR 42—General Safety Requirements’ states that:
“no vehicle must be equipped with any object or fitting, not technically essential to such vehicle, which protrudes from any part of the vehicle so that it is likely to increase the risk of bodily injury to any person”.
Interpretation of this ADR hinges on what’s meant by “Technically essential” and the argument of what happens when a vehicle fitted with a bull bar hits a pedestrian. The purpose of a bull bar is to prevent energy being dissipated through the body of the vehicle when it strikes an animal. This means more of the energy of the impact is taken by the animal’s body than the vehicle. Exactly the same physics would apply in the instance of the vehicle hitting a pedestrian.
As a result, most state registration bodies including VicRoads skirt this part of ADR 42/04 and instead refer to compliance to Australian Standard AS 4876.1 2002. We can take the following out of the requirement:
- The bull bar shall follow the profile of the vehicle to which it is fitted.
- Fitting the bull bar must not increase the width of the vehicle (excluding the mirrors).
- Any sharp edges on the bull bar shall be chamfered or radiused.
- No open-ended frame members are allowed.
- No small components (such as brackets) shall be attached to the front of the bull bar.
But the story doesn’t end there. For the past 15 years or so vehicles have had to comply with ADR 69 and ADR 73 which requires vehicles to protect occupants in a front-on crash. In modern vehicles, compliance with these ADRs can be dependent on a predictable rate of deformation of the front-end structure. Also calibrating airbag deployment is a precise thing and how this is affected by additional structure attached to the front end is very much dependent on how well it’s designed and mounted.
To maintain compliance with these two ADRs, VicRoads in addition to the Australian Standard Compliance also require (in its own words) that any bull bar fitted to a vehicle that is subject to ADR 69 and ADR 73 must demonstrate that it:
- Has been certified by the vehicle manufacturer as suitable for that vehicle; or,
- Has been demonstrated by the bull bar manufacturer to not adversely affect the vehicle’s compliance with ADR 69 or ADR 73 or interfere with any critical air bag timing mechanism as the case may be.
For their part, RACV think bull bar manufacturers need to put their resources into continuously improving their designs to be not only compatible with roadworthiness requirements but to minimise injuries to unprotected road users.