Question Re How To Calculate The Speed Of The Other Car In A Collision

[JackInCT-USA]

Hi,

I'm wondering if it's technically possible that, in a scenario of a car colliding with mine, whether I would be able to reasonably ESTIMATE the other car's speed from my dash cam video. This would be a DIY effort. I'm looking for software tools, kinds of skill sets needed, etc., to be able to do something like that.

Thanks,

Jack

 

[jokiin]

could you work out yourself, maybe, it's more about mathematics than magic, speed is just time taken over distance traveled, known reference points could provide location information, measure between two points and see the time taken to travel that distance, it gets harder if you're moving toward the target as your speed and distance traveled would need to be subtracted, add to that if you were measuring something coming straight at you your position relative to the target is not ideal to be able to measure its location at reference points, could it be done, I think so, are you likely to be able to do it accurately yourself, maybe not, you're really getting into forensic science that is beyond what's probably reasonable

 

[horaceCJ]

Like jokiin said, speed is the distance traveled in a certain amount of time. The later is pretty simple to use as you have the clock on your video, or you can count the number of frames (usually 30 per second). Then you need the distance from the point where the vehicle was in frame 1 to the point where the car was in frame 31. That you can get in different ways, for example:
- go back to the scene with printouts and a measurment tool
- look for standards like: distance between 2 electrical poles, distance between/of road markings etc.

LE: then, if you don't like math, you can go here to convert the result to whatever unit you want.