Abstract: A device, which is attachable to a bicycle, extends out laterally from the bicycle in a direction toward or into a lane of traffic. The device may be approximately three feet in length and cylindrical in shape. The device serves as a reminder of the leeway that must be given between a bicycle and a passing car, and deters drivers of passing automobiles from encroaching within three feet of the bicycle to which the device is attached. The device is constructed of a flexible polymer material, preferably polyethylene foam. The flexible construction allows the device to flex upon impact by a passing vehicle, thereby preventing substantial effect upon the trajectory of the bicycle and preventing damage to the vehicle. The device can be designed in two parts which can separate in the unlikely event that the end becomes attached to a passing vehicle.