Question:

An emergency vehicle has stopped ahead with its flashing lights on. What must you do?

A If possible, leave an empty lane between your vehicle and the emergency vehicle; otherwise, slow down.

Explaination

Try to leave an empty lane between your vehicle and an emergency or maintenance vehicle that is stopped with its flashing lights on. If this is unsafe or not possible, you should slow down and proceed with caution. [Emergency/Maintenance Vehicles, Chapter 4: Traffic Laws, Illinois Rules of the Road]