Once the crash frequencies, types, and severities are identified, conduct a crash pattern analysis using a collision diagram. Collision diagrams visually display locations and types of crashes by direction of travel to facilitate identification of patterns and clusters. Recognizing over-represented or target crash patterns helps identify which control type countermeasures can help prevent those crash patterns from reoccurring. For example, installing a traffic signal could help reduce the number of right-angle crashes. See

Figure 10-11

for an example of an injury collision diagram. See

Appendix K, Section 9 – Crash Diagram Template

for a template of a crash diagram.