Sintra Engineering | Resolve Matters

Western Canada's
Forensic Engineering Experts

Sintra Engineering

We are committed to writing technical articles and publications.


Take a look at the topics below.

Resources

Talk to an expert at:

1-877-244-6251

‹ View All Posts


Clarifying Collisions: Getting a Grip on Left-hand Turns


Sintra Engineering is committed to expanding our knowledge in subjects pertinent to our investigative practice areas. We are currently engaged in research that analyzes the path geometrics and dynamics of left-turning vehicles at intersections.

A common scenario that leads to a motor vehicle collision occurs when a left-turning vehicle collides with an oncoming vehicle at an intersection. Usually, there are no roadway markings to verify the path taken by the left-turning vehicle –– skid marks resulting from applied brakes are not often present because the left-turning vehicle driver is normally focused on completing the turn. As such, in order to reconstruct the collision, assumptions have to be made with respect to the path taken by the left-turning vehicle and the dynamics of the vehicle as it made its turn (e.g. where did the vehicle stop, how did it accelerate). These assumptions can be subjective and vary greatly depending on the individual doing the reconstruction.

Due to a lack of published literature on this topic, we have embarked on a research project to provide us with a more objective means of predicting a vehicle’s left turn path. We are documenting and analyzing vehicle turns in order to evaluate how they are conducted and what factors influence the nature of the turns.Without delving too far into the technical details of the project, the following is a brief overview of what we’ve done thus far.

  • In order to obtain empirical data, we videotaped a busy, urban intersection at different times of the day from as high and directly above the intersection as possible to record vehicles making turns
  • We surveyed the intersection so that we could use point tracking software to record the vehicle paths
  • Photogrammetry was applied to correct for the fact that the video camera (being situated in a tall building on one corner) was both offset from the intersection and not facing straight down on the roadway
  • The vehicle trajectories were analyzed to evaluate the general paths taken, how fast the vehicles were traveling, and how the vehicles accelerated through the turns
  • We considered several potentially influential factors that may affect driver behavior and vehicle paths including travel directions, traffic light status, type of vehicle, distance to oncoming vehicles and whether vehicles stopped before making a turn
  • We are finalizing a summary of preliminary results from the one intersection and preparing a methodology that can be applied to other test sites

The results obtained to date provide an overview of the location, speed and acceleration of left-turning vehicles at the particular intersection. These can be combined with data collected under different circumstances so that predictive models can be developed. Consequently, when there is a lack of physical evidence confirming a vehicle’s pre-collision motion, our findings will enable us to better predict a vehicle’s left turn path and reconstruct the events leading up to a collision. This will enable us to provide our clients with more precise results and decisive opinions.


Next Post ›‹ Previous Post

Familiar Faces

Carla

Carla

Carly

Carly

Mark

Mark

Jeff

Jeff

Claudia

Claudia

Tony

Tony




Subscribe to Our Newsletter



Click here to Subscribe ›


Follow Us On Twitter