Tag Archives: stopping

Speeding and the three second rule

Like so many people, I nearly had someone crash into the side of me as they changed lanes. I’m pleased to say that I braked just the right amount so to avoid being hit by this car; I’m also pleased to say that I also avoiding the person behind me rear ending me, phew!

This however got me thinking about how my experience and similar ones could be avoided. My first reaction was about the car and the driver that nearly hit me, but at the end of the day at some point everyone will make a bad judgement on the roads and will have a near miss; its going to happen. I then began to think how much easier my situation would have been if the car behind me wasn’t so close.

I checked and there are laws, with penalties, to ensure that cars need to be a certain distance apart; however as far as I’m aware there is no electronic deterrent stopping people driving bumper to bumper. This is of course unlike speeding.

Certainly from my own experience people are far more likely to drive bumper to bumper then speed past a cop car. I think that few would disagree that the reason behind this is you are far less likely to get charged for it. I believe one factor in this is that it is hard to prove this is the case without an electronic record. Though for completeness there will be a video record in the cop car, but to my knowledge no system to alert an officer of a breach.

The question is, does this have to be the case? Could current technology be adapted, or built on, to deliver a combined solution(speeding and detecting distance) to help with road safety?

Fundamentally all a device needs to do is measure the time between one motor vehicle and the next. If its to short a time for the given speed then it can alert the user, hence of course the term the “3 second rule”.

As far as I can see there are two fields of technology that could potential be built on to deliver this. The most restrictive, and I would envisage simplest, is using RF “toll” road tags. Key factors that would have to be looked at is the RF pickup range(false pickup from another lane) and the response time, though I would think such a system is possible.

This however is restrictive as it only works if the offending vehicle in-front both have an RF device installed…

The other field is of course vision system, in particular ANPR(Automatic Number Plate Recognition) system. Though no vision processing is a trivial task, the journey from nothing to our current system is very much larger than from where we are with some additional inter-plate timing additions.