The Economic Commission for Europe is studying a test procedure to evaluate the protection of passenger car occupants in a lateral collision. This procedure proposes a collision test with a mobile deformable barrier. This document: defines the mobile deformable barrier characteristics, reminds the work carried out by U.T.A.C. to study and develop a mobile deformable barrier which meets the requirements of the E.C.E. procedure, describs lateral collision tests carried out with the mobile deformable barrier against cars representative of the European market, gives the results of these tests obtained in the dummies of the struck vehicles, on the car structures and on the mobile deformable barrier.