Calculating Speed from Yaw Marks
When a vehicle is in yaw it is rotating around a vertical axis through it's centre of mass. The long, curved yaw marks left by the tires on the pavement were characteristic of this motion. If they were striated and of constantly diminishing radius they were of great interest for collision reconstruction because the vehicle's speed could be determined from them.

Question: My son was ticketed with driving too fast for road conditions. The air and roads were dry so there were no road conditions. He was in an unfamiliar area at night and was in a roundabout which had a steep ditch on one side. As he was unfamiliar with the roundabout, he simply turned into the curb instead of following the curve of the road, and ended up over the curb and slightly down the embankment.
Question: The police officer used a radar gun to check my speed. According to him, there are no records for radar calibration on it. This is a real, live issue for my trial. If the radar gun does not have service records, then how do we know that it is functioning correctly?
Welcome to wet weather season in British Columbia! Some areas are blessed with this situation more often than others, but drivers need to be aware of the perils of wet highways. The well being of you and other road users depend on it.
Question: Our daughter failed her road test due to not reducing her speed to 30 km/h as she drove through a playground zone. We don't understand this because there were no signs were present.
Today was the first day back at school for elementary students where I live. The school is on an arterial road with a posted speed of 60 km/h that is often ignored by many drivers. I stood with speed watch volunteers for an hour from 10:00 to 11:00 am and was pleasantly surprised by what I saw.
This case is an appeal of a traffic court conviction where the officer who issued the ticket used a visual observation of vehicle speed to base the ticket on. The estimation was 90 km/h in the posted 60 km/h zone on the Lougheed Highway near the North Road intersection.