Why wouldn't Joe Citizen with a cell phone work? There was a very erratic driver in front of me and I called 911. Gave them a description of the vehicle and where they were headed. They pulled into a parking lot, and I described their location as the police showed up. The person admitted to talking on their cell phone while driving which caused them to do all the things drunks typically do - couldn't stay between the lines and missed a stoplight turning green and just sat there at the green light. That's what I reported to 911. I was on the other side of the parking lot and the officer came to me and thanked me for calling them, that I had reported someone that was clearly a danger to other motorists.