Simplified analysis of vehicle change in momentum during impact with a breakaway support. Paper prepared for the 55th Annual Meeting of the Transportation Research Board TRB, Washington, D.C., January 1976.

The impact of an automobile with a breakaway support for a sign or luminance can be devided into three phases. Using simplifying assumptions, the contribution to vehicle change in momentum (? MV) by each phase can be determined. Results of this analysis are that ? MV can be approximated by a formulation. This formulation has provided valuable insight into the effect of vehicle stiffness, breakaway force level, base fracture energy, pole inertial properties and vehicle impact speed on ? MV.