The traffic signals in my part of town have optical sensors that recognize a bicycle wheel, using a sophisticated algorithm. You roll up to a hold line, turn the wheel slightly and voila, the light changes. Traffic engineering has scanned in catalog images of the most common wheel designs, and the system can tell if you're on Campy, Shimano, Enve,etc. If you're riding a piece of crap bike, you will not trigger a light change. You can take your bike down to Traffic Engineering and they will calibrate their system to work even quicker, especially if you have a unique spoke design and pattern. They will issue you a UTCDP* that will also trigger the light. *(Uniform Traffic Control Device Passport)

This frees up our hard working LEOs to handle important public safety issues...