They do one thing well, and that's to reduce the driver's anxiety, as long as you don't destroy his illusion. Here in the US, they're sold primarily to reduce deer collisions. But they're a scam. One study from the University of Wisconsin showed that of the whistles tested, they only emitted at approximately 35 mph (56 kph). And the sound they made was outside the hearing range of all deer species in North America. At about the same time that study was being done, the State of Georgia, if memory serves, put deer whistles on 50% of their motor vehicles via random assignment. After one year, there was no difference between the vehicles with and the vehicles without the whistles in regard to the number of deer strikes.
They do one thing well, and that's to reduce the driver's anxiety, as long as you don't destroy his illusion.
Here in the US, they're sold primarily to reduce deer collisions. But they're a scam.
One study from the University of Wisconsin showed that of the whistles tested, they only emitted at approximately 35 mph (56 kph). And the sound they made was outside the hearing range of all deer species in North America.
At about the same time that study was being done, the State of Georgia, if memory serves, put deer whistles on 50% of their motor vehicles via random assignment. After one year, there was no difference between the vehicles with and the vehicles without the whistles in regard to the number of deer strikes.
Yep. I forgot to add the link from the testing of the electronic ones here in Australia... in short they were no better off either