Distance sensor for drafting

[sallen]

This is a relatively simple arduino project, but something outside the range of the standard hobby sensors (Sharp IR and HC 10x ultrasonic?) - 60cm and 4m respectively.

Maybe some kind of inexpensive laser time of flight sensor could be hooked up to a speed sensor.

[Piwoslaw]

So are there any radar sensors with 100m range available in the amateur hobbyist price range?
Or at all?

[redpoint5]

Looks like $400 used on Ebay. You need 2. Then you need vehicle speed sensor, a controller to make sense of all that and output a throttle control signal.

[MeteorGray]

The three-second rule is a good one for safety, flexibility and legality. It's easy to employ without having to take your eyes off the road. We do it in my area of the world by saying "one Mississippi" for each second of time being gauged.

I used to use a vacuum gauge installed on the intake manifold to see the beneficial effects of following a big truck etc. Nowadays, I have a ScanGauge with instantaneous MPG readings to do the same.

One of the big things I keep in mind when following a vehicle in traffic is that rear-end accidents can be expensive and even lethal, and that the guy who does the rear-ending is almost invariably at fault.

[Grant-53]

I use the 3 sec. rule as reaction time is critical. I have no way of knowing what the vehicle and its driver will do next. I would not want someone drafting me with out radio contact to coordinate actions. Just how close is close enough to gain any advantage?

[freebeard]

According to aerohead: