While traveling at about 40 mph on a motorcycle and then grabbing only the front brake is probably the last thing someone would want to do, but that is exactly what Oro Valley police officers did last week for a traffic reconstruction class.
The class, which was put on by Northwestern University, focused specifically on the dynamics of a motorcycle during a collision.
From using Anti-locking Brake System (ABS) to using only the rear wheel, on wet pavement, without ABS, numerous scenarios were run through. After which members of the class would measure the skid marks, take pictures of the tires, and look to better understand how each variable alters the physical evidence left on the road.
Oro Valley Police Department’s Lt. Chris Olson said the advanced class was able to see and better understand how the coefficient of friction affected the type and length of a skid.
After testing different types of skid marks, the class instructor, Mike DiTallo, sat on the back of a truck and rolled salvaged motorcycles off the lift gate at about 40 mph to show what a skidding motorcycle looked like and more importantly, the evidence it leaves on the road.
Members of the class were able to see what specifically happens when a sports bike, with plastic fairings, skids, and then compare it to what happens when a big, heavy motorcycle with a lot of metal slides on its side.
“Investigators will have a better idea of what causes things to skid as far as they do and also give us a better idea of estimation of speed,” Olson said.
The advanced class dove into a specialty of crash scene investigation. DiTallo said motorcycles are completely different from cars due to the variances in the weight of the bikes, the independent front and rear braking, the experience of the rider, and the speed at which the bikes travel.
Each of these variances leaves behind specific evidence, which is then used to help determine the cause of the accident.
“We are showing them that evidence,” said DiTallo. “We’re showing them what happens when you have ABS, no ABS, front brake, rear brake.”