Mostly from airport. And these were only the ones caught. As a local I am frequently asked by airport cabbies "do you want to take the tunnel?" Which is the same as asking "do you know your way around?" When I say I don't know they take me the long way about half the time. I have filed several complaints over the years. Visitors beware.
http://www.reviewjournal.com/lvrj_home/2004/Feb-22-Sun-2004/news/23183279.html