COLLISION INVESTIGATION

Each and every collision has something individual about it. It follows that each collision investigation is quite individual. There is no set pattern although there are several common factors.

For the vast majority of cases where a collision investigation report is required the event is “in the past” – in a civil case usually a few months have elapsed and in a criminal case the Police have attended and prepared their own report.

In Civil cases the report is often required where liability is in dispute. The greater the degree of personal injury the more likely it will be that liability is disputed. A point is reached where it becomes proportionate and justifiable to have an independent collision investigation report carried out.

In Criminal cases it often occurs that one’s liberty is at risk following a collision hence it is most appropriate that any investigation carried out by the Police is at least challenged in the interests of justice. It does occasionally happen that the Police have miscalculated a vehicle speed or misinterpreted some data. Sometimes even the way that a fact is presented can unintentionally mislead a jury.

The following is an example of some of the methods used in a collision investigation:

• Calculation of speed from tyre skid marks.
• The speed of a vehicle negotiating a bend from critical speed marks.
• Vehicle speed based on pedestrian throw.
• Pedestrian walking and dart-out speeds.
• Acceleration tests.
• Sight lines.
• Using similar vehicles to reconstruct motion.
• Measurement of lighting levels.

You are requested to view some of the case studies on this website in order to appreciate what goes on and the depth into which some investigations can progress.