How can a motorist potentially cause a car-bicycle crash when pulling away from a stop sign?

A motorist can cause a car-bicycle crash when pulling away from a stop sign primarily by failing to yield to bicycle cross traffic. At a stop sign, the expectation is for the driver to come to a complete stop and assess the traffic, including any cyclists approaching from their left or right. If the driver does not properly yield to bicyclists who have the right of way, they may unintentionally initiate a collision.

Bicyclists often have the same rights and responsibilities as motor vehicle users, and if they are legally crossing the intersection while a vehicle approaches the stop sign, the vehicle must yield to them. This responsibility is crucial because most drivers may not see bicyclists as easily as they see other vehicles, increasing the risk of accidents if drivers do not pay full attention.

In this context, the other options do not relate specifically to the failure to yield to cross traffic. Exceeding the speed limit, making an illegal U-turn, or honking at bicyclists do not directly pertain to the risks involved in pulling away from a stop sign in relation to bicyclists. The latter actions may contribute to unsafe driving but do not specifically cause a crash during the critical moment of yielding at an intersection.