Lane-sharing is the practice by a motorcyclist of sharing a lane with another vehicle. Lane-splitting is the practice by a motorcyclist of riding between streams of traffic by riding on or near the striping between lanes. Filtering, which seems to be a term frequently used outside of the United States, is the practice by a motorcyclist of riding between lines of stopped or nearly stopped traffic at a traffic signal. The terms lane-splitting and lane-sharing are often used interchangeably and often the term lane-sharing is used as a catch-all term for all of these practices. These practices, which are allowed in California, allow a motorcyclist to drive faster than the surrounding traffic in congested or stop-and-go traffic [1, 2]. They also give motorcyclists more options for how they position themselves on the roadway, allowing them to “strategically place themselves in pockets of lower congestion during commute traffic” and to “distance themselves from safety hazards from larger vehicles beside or behind them, or from hazards presented by highly congested clusters of traffic” .