The following is something they are doing in Colorado which I think is kind of cool. While you can report aggressive drivers here in Maryland via *77 on a cell phone we do not have the follow up they do in Colorado.
Bicyclists have a new tool to help make Colorado
The phone number is Star CSP (*277) when dialed from a mobile phone. Thanks to a State Patrol partnership with mobile phone companies calls to this hotline are free.
This is not like a normal phone number; you do not need to dial an area code. Simply press the * key (usually the lowest left key on a phone pad) and then 277. This number only works on mobile phones. If you are calling from a non-mobile phone dial 303-239-4518 or any State Patrol Communication Center. In the case of an emergency dial 911.
Bicycle Colorado confirmed bicyclists' use of this hotline during discussions with the State Patrol to remove the cap on bicycling events.
When dialing Star CSP bicyclists should be prepared to communicate: