DUI Protocol

As I drove to dinner tonight, I came upon an accident scene. The police were already there, a motorcycle had been involved, and was turned on its side. The police had the area around the motorcycle roped off from traffic, and were guiding traffic around it. I assume the ambulance had already come and gone, as the driver was no where in site. The restaurant had a clear view of the scene, so I watched it unfold. The police continued to guide traffic, and then the fire department arrived. As we left the restaurant, we noticed a large police DUI Enforcement bus that was not there when we went into the restaurant. Anyone know DUI police/accident protocol? Why the late arrival of the fire dept and DUI Enforcement bus?
I've seen those paddy wagons around when they do check points so they can transport larger groups of people to where ever they're going (hospital for blood draw, central booking, etc)

The fire department was for clean up of glass & debris on the roadway.The arrival of the "DUI bus" was probably a coincidence ... a checkpoint had already been arranged for enforcement in that area that particular evening.

Some sort of major sporting event or a concert going on in the area?

Quote from ScottESome sort of major sporting event or a concert going on in the area?

There are no sports going on now except baseball. Maybe the rescue unit scooped and ran with the Donorcycle rider and let the FD do damage control on scene. Who knows.