Best Guess: What’s This Firetruck Driver Doing?

Any fire fighters out there know what’s going on here? Because, no he’s not drifting and yes, it does have a purpose!

Its referred to as a “moving road block”. They use this technique to try and prevent people from passing the fire engine as they approach an accident. When people are trying to pass, when the driver is planning for a turn, and when preparing to slow/stop traffic to arrive on the scene is when this is used.