Final answer:
A person may only drive over an unprotected fire hose if they have explicit permission from the fire department official in command, as doing so without permission could hinder firefighting efforts and endanger lives.
Step-by-step explanation:
A person may drive a vehicle over an unprotected fire hose laid down on a street at a fire emergency only if they have received permission from the fire department official in command. This rule is based on the need to ensure the safety of both the firefighters at work and the victims they are trying to rescue. Driving over a fire hose without permission could damage the hose or disrupt the water supply, hindering firefighting efforts and potentially endangering lives.
In an emergency situation such as a woman being in labor in the vehicle and needing urgent medical attention at a hospital, an exception could possibly be made. However, it is crucial that this decision is conveyed to and permitted by the fire department official who is in command of the fire emergency scene. Without this explicit permission, one should never assume it's safe or lawful to drive over a fire hose, regardless of the emergency one might personally be facing.