Just curious: How do these motorcycle groups get police escorted rides with the cops blocking all traffic so they don't have to stop at red lights?

I've seen this a number of times with the Detroit Police Department. Today, for the first time that I have seen, there were 8 Wayne County Sheriffs escorting a motorcycle club/group on a ride down Woodward.

Do the groups PAY for these cops? If not, it seems a waste of taxpayer money. Just curious how this works. It's only May and I've already seen this at least 5 times this year.

Thanks