Speed is fun, but be reasonable. Racing is for the race course. Noise is a serious problem for wildlife, as well. Speed is noisy. Hooting is for hooters.
Silence is a common courtesy to every living creature present in the area.
If you want to really understand the problem hide along a canyon wall and listen to people pass by. Boy, are we noisy. Small water pockets on the rock leave dry blackened pits that should also be avoided. There are fragile and extremely rare life forms in those blackened pits and water pockets. Most importantly, don't let your dog run or wallow in these tiny ecosystems.