In an effort to thwart drivers using blow-up dolls to go on carpool lanes, British officials are testing a new system called the Cyclops cam that can detect the number of passengers in a car from 160 feet away. The camera employs the fact that human skin contains a measurable amount of water. So far, the camera is 95% accurate.

http://news.scotsman.com/scitech.cfm?id=2319702005

So fill your blowup dolls with water. Dur...

First of all, there is water that is actually inside the layers of skin. Whereas blow-up dolls, which are usually made from plastic, cannot actually absorb the water. The object itself will be filled with water, but the plastic, which is the "skin" will not absorb any water at all. I'd like to actually see you try filling up a blowup doll with water and driving around the Cyclops cam.

The "skin" doesnt have to absorb water. The "skin" just has to be thin enough for the cam to register it as containing water. And I wouldnt care to do so as there isnt squat for car-pool lanes around here, theres about 3 or 4 cops the entire length of the interstate running the length of Maine, and I have no problem going faster than those in the carpool lane staying in the normal one.

If people could trick the camera by merely filling up their dolls with water, I think they would have figured that out by now.