Like someone else has said, with motors, it runs better, they can move easier and quicker, and not run other cars off of the road like these guys were doing.
But in California, for an officers funeral, one was struck and killed by another officer, so they are dangerous too.
I also think that procession lead car, was moving WAY too fast. They need to slow down, and the blocker cars would not have to race to get ahead.
When I worked as a cop in Arkansas, I ran an escort for one. I was the only unit for it. It was a smaller town, and all we did was pretty much start it out of the funeral home, and lead the way, when we came up to turns and intersections, I just made sure everyone was stopped, then went, the procession followed and no one tried to get in the way.
But it should be noted, in a 6-7 square mile city, we did not have ANY stop lights, and we had a major two lane highway running through it. So I did not have any huge intersections to compete with. Everyone just stayed in line and we all made it there. The funeral home was on one side of the city, the cemetery on the other, both were along the highway, so we took the highway, which ranged from 25-45 MPH speed zones. We cruised at about 25 MPH the entire time, when we reached it, I just blocked the on coming lane, everyone filed in, and when last car was in, my lights we off, and I went back on duty.
There were sometimes that they did not use the cemetery in the city, and went a next town over, which was about 15 minutes away, so we would hand off the procession to the county SO at the city limits, they would take it to the next city, and hand it off to their PD.