Bad car or bad bike?

[dui546]

Your choice to use this video for discussion Dan is awesome...Good Job!

I initially looked at the vehicles in motion and made my guess of speed based on my visual observation and tracking experience using radar or lidar.

OK, by reviewing the video and totally guessing by using sight comparison measurements conservatively....each line in the road is about the length of one compact car (using a car in ref to the line as it passes). Let's give the car a rough guess length of 12 ft (it could be 13-14 ft). 4 lines X 12 = 48 ft. Plus, you have a space between each line that is about 1 1/2 car length or approx 18 ft using a 12 ft car. 4 X 18 = 72 + 48 = 120 divided by 3 = 40 fps. That would put the veh speed at about 30 mph on the low end. I went short on the approximate car length so I would probably guess the vehicle speed would be more around 35 mph. The motorcycle seemed to enter the screen a little quicker. Therefore, I would stick with my original evaluation. The driver of car deserves the increased insurance rates.

When we do calculations of evidence based on true measurement using measuring tools or survey equipment (skid or yaw marks, reference points, evidence points etc), we always give the offender the benefit of speed we calculate. In other words, we calculate the minimum speed that the vehicle would have been traveling. A video guess is relatively difficult without being able to obtain concrete reference measurements. However, it could be done using a vehicle of like make and model as any of the vehicles that pass by the lines in the video frames.

Again, Dan, you picked a good video based on the desired conversation.