While acting under Law Enforcement, you are to follow every single road law. That does of course consist of times you don't have too.
Not needing to following general road laws
Responding to a Code 3 required call
Responding to a Code 2 required call
Panic button press
Vehicle Pursuit
New road laws in pursuit
While in a pursuit you are permitted to break certain laws in pursuit of justice, HOWEVER new laws come to when your acting under these situations
Red lights, and intersections
Slow down
Check both ways
Go
Highway
Evaluate your speeds
You may go fast
Know when to put on the brakes
Stop signs
Slow down
Check both ways
Go
While clearing a intersection it is recommended to lay on your horn as to let it be known that you are pulling up to the intersection and going through it.
Failure to clear intersections properly while responding to a call could result in colliding with another vehicle, and trouble with your Departments High Command.
The only time you don't have to clear intersections is when in pursuit of a subject but still be aware of your surroundings.
No matter your rank, If you break a traffic law you can be pulled over by a fellow officer and talked to about it. We are the police but still must follow the law.