Crashes at intersections can involve an on-coming vehicle versus a left-turning vehicle, cross traffic and, even on rare occasions, two vehicles turning in the same direction where one strays out of their lane. By far the most common is an on-coming versus left-turning situation. In those cases the main issue is frequently the speed of the on-coming driver and whether the left-turning driver could have, or ought to have, been able to tell whether that vehicle was a hazard before they started their turn.
Not all issues are relevant to every case, but some of the more usual issues are:
We start by calculating the speed of each vehicle. We then do a “time/distance analysis”. That means we back each vehicle up in time to see how far they were from one another and from important landmarks, such as entering the intersection, as they approached. This is very useful in terms of determining who entered the intersection first. It is also the foundation of the further analysis regarding who ran the red light and/or was one vehicle visible when the other started moving, and how avoidable the crash was for the driver.