Abstract
This document presents problem size assessments and statistical crash descriptions for backing crashes and several key subtypes of backing crashes. Backing crashes are a potential 'target crash' of high-technology Intelligent Vehicle Highway System (IHS) crash avoidance countermeasures To elucidate potential countermeasure applicability, backing crashes are divided into two types: encroachment and crossing-path backing crashes. The emphasis of this report is on the encroachment backing crashes, in particular encroachment crashes where the vehicle is under control. The subclass is likely to be most amenable to prevention by an obstacle detection system. (Author/publisher)