Many road traffic cases are not clear cut

Road traffic accidents (RTAs) are not always straightforward. For example, in a recent case it was suggested that a collision, which led to the death of one of the drivers, was because our client had been on the wrong side of the road at the time of impact. While our expert was able to confirm this, there was more to the investigation than that.

Consideration of the damage to the vehicles suggested that, although the victim’s vehicle was pushed backwards in the crash, suggesting that our client was travelling at excessive speed, examination of the roadway and images from CCTV cameras showed that our client was travelling within the speed limit and that the victim was the one exceeding the speed limit by a considerable margin.

Furthermore, the victim was not wearing a seat belt. Had they done so, they would not have sustained such serious injuries and the outcome may have been different.

Collision dynamics

The investigation of RTAs is often complex and may involve a number of different areas of expertise, from collision dynamics, vehicle examinations, consideration of road and weather conditions, examinations of mobile phones, vehicle computers, CCTV footage and so on.

It is therefore crucial that clients use the services of companies with an established reputation and the broad range of areas of expertise that such investigations warrant.

The analysis and reconstruction of vehicle collisions and accidents is a highly specialised discipline, which takes into account physical evidence, witness evidence, vehicles involved, road topography, weather conditions, vehicle dynamics, driver reaction times and driver behaviour.

Accident-involved vehicles and their component parts can be examined for any defects or failures. This can help to find the cause for any particular accident. It can often come as a surprise to learn that light bulbs can be examined to prove whether or not they were lit at the time of collision.

When undertaking collision reconstruction, experts take into account tyre grind and slide marks, pedestrian throw distance (if applicable), speed and movement of pedestrians, co-efficient of friction, driver reaction times, mass of vehicles, vehicle performance, vehicle test data and position of vehicles at impact.

All are modelled mathematically in combination with the laws of motion in order to determine vehicle speeds and event reconstruction.

Experts in RTAs use standard and digital photographic technology to illustrate road markings, geometry, topography, signing, lines of sight, limits of visibility, positions of witnesses, pre- and post-impact movement of vehicles/pedestrians, vehicle damage and defects.

Using the latest electronic total station surveying equipment, experts produce professional computer-generated scale plans of accident and crime scenes; we can also produce scale representations of vehicles and show these in relation to physical and witness evidence demonstrating the position of vehicles at impact and ultimately providing a visual reconstruction of the accident.

Forensic analysis

Road traffic work not only covers accident investigation and reconstruction, but can also include the microscopic forensic analysis of tachograph charts to analyse route traces and verify drivers’ hours to see if they comply with updated regulations.

Stolen-vehicle examiners look at the prosecution evidence, investigate the potential retrieval of deleted VIN and engine numbers, and can often undertake the dating of components and vehicle glass. In cases where there are allegations of vehicle ringing and handling (including conspiracy), an expert is able to test the findings and conclusions drawn by the police, offering, where possible, alternative explanations.

Some experts are also trained in all aspects to do with police speed detection devices including Vascar, Muniquip radar, police pilot and Laser LTI 20-20. These experts can test the accuracy of the speed checks, procedures and circumstances under which they were conducted. SJ

Nicola Beckwith-Elliott is the owner of Emmerson Associates