Wedges are quite effective tools for using forces in directions perpendicular to the applied force. In a collision, vertical components, if allowed to be raised, can lift the rear end of trucks and buses, thus aggravating the underride effect and consequences.
WHEN IS THE WEDGE EFFECT PROMOTED?
of the wedge effect in a real accident occurred in Australia:
NOTE: IN A CRASH TEST PROMOTED BY UNICAMP, GENERAL MOTORS AND MERCEDES BENZ, A SMALL GM CORSA WAS ABLE TO LIFT A PARKED TRUCK WITH A 10 TON LOAD, SOME 15 CM.
During braking, car front bumpers can have their height substantially reduced in relation to the ground, and as a light vehicle's suspension is soft for comfort reasons, this height reduction can be extreme, promoting even more the underride effect.
CONCLUSION: THE WEDGE EFFECT IS EXTREMELY IMPORTANT AND CAN NULLIFY AN APPARENTLY EFFICIENT UNDERRIDE GUARD. THEREFORE, IT CANNOT CONTINUE TO BE NEGLECTED IN ALL RULE MAKING PROCESSES.