Final answer:
A red "X" over a lane indicates that travel in that lane is prohibited. It is a traffic control measure used to prevent vehicles from entering a certain lane.
Step-by-step explanation:
A red "X" over a lane indicates that travel in that lane is prohibited. It is a traffic control measure used to prevent vehicles from entering a certain lane. This is typically seen in situations such as road construction or accidents, where a lane needs to be closed off for safety reasons.