Final answer:
Vehicles are generally not allowed to share a lane with a motorcycle, with exceptions like lane splitting in certain places. Sharing a lane reduces a motorcycle's space to maneuver and increases accident risks.
Step-by-step explanation:
In most situations, it is not permissible for a vehicle to share a lane with a motorcycle. Motorcycles require a full lane width to operate safely, just like any other vehicle, and lane sharing can be very dangerous. There are specific exceptions like California's lane splitting law where motorcycles can ride between lanes of stopped or slowly moving cars, but even then, cars themselves cannot share the lane with a motorcycle. Sharing a lane typically reduces the motorcycle's space to maneuver and increases the risk of an accident.
In a situation not explicitly listed, it is always best to assume that lane sharing with motorcycles is not allowed and give them the full lane they need for safety.