Impeding traffic is typically defined when not operating a vehicle reasonably, so as to block the normal flow of traffic. It typically is used in cases where a person is blocking an intersection or driving too slow and causing a log jam. Laws vary by jurisdiction, but are generally follow a standard of "reasonable operation". The following is an example of a state law governing impeding traffic:
" 169.15 Impeding traffic.
No person shall drive a motor vehicle at such a slow speed as to impede or block the normal and reasonable movement of traffic except when reduced speed is necessary for safe operation or in compliance with law or except when the vehicle is temporarily unable to maintain a greater speed due to a combination of the weight of the vehicle and the grade of the highway. "