Time Distance Analysis
What opportunity did the driver and/or the pedestrian have to avoid the collision?
If either could go back in time and re-live the incident, what would they have done differently to avoid the actual outcome? Many times, it relates to visibility and time. However, it is almost always paramount to establish the speeds of both at the moment of impact. We can do that!
MDA experts use a combination of scene evidence and established physics procedures to pin down the impact speeds. Once that is done, we can immediately establish the positions of both at discreet time points prior to the impact. Some of those time points are critical to establishing the avoidance potential such as “ point of last opportunity “ and “ point of first perception “. We can establish these points precisely for you and illustrate them in 2D and 3D static drawings as well as in moving animations both in 2D and 3D which are very persuasive tools. Clarifying the pre-impact positions and timing is key to success.
Types of Pedestrian Collisions
The five different types of pedestrian collisions are:
The most common type of pedestrian collision, which usually involves a decelerating vehicle. In this type of collision, the pedestrian’s torso wraps up onto the vehicle’s hood.
This is the most common type of pedestrian collision that occurs with children. This type of collision occurs when the pedestrian’s center of mass is lower than the leading edge of the vehicle.
This type of collision involves both vehicles which are braking and non-braking. The pedestrian is contacted near an outboard edge: the torso is wrapped onto the hood of the vehicle, and the pedestrian exits off of the side of the vehicle.
This type of pedestrian collision occurs when a pedestrian center of mass is higher than the leading edge of the vehicle. The pedestrian is lifted into the air because of the vehicle’s speed or a low roof line. Typically, these types of pedestrian collisions are caused by high impact speeds.
This is the least common of pedestrian collisions and is due to high impact speeds. The pedestrian is flipped into the air (or is somersaulted) before striking the ground.
Determining what type of pedestrian collision requires an analysis of the collision scene, a vehicle examination and an examination of the pedestrian’s injuries. From the analysis of these examinations, a crash reconstructionist will be able to determine how a person was contacted by the vehicle, if the person went up onto the vehicle, how the person fell to the ground, and what occurred while the pedestrian was on the ground.