That's A Lot Drunk Irish And A Lot Of Cops

From the Las Vegas Sun:
A total of 30 people were arrested on counts of driving under the influence at a St. Patrick’s Day sobriety checkpoint to identify impaired drivers before they got into wrecks, Metro Police said.

The checkpoint on Paradise Road, just north of Tropicana Avenue, was set up from 7 p.m. to 3 a.m., police said.

Of the 2,048 vehicles that passed through the checkpoint, 88 people were tested for impaired driving, police said. A total of 27 officers were assigned to the checkpoint.  http://www.lasvegassun.com/news/2015/mar/18/metro-police-arrest-30-st-patricks-day-dui-checkpo/
Ok, good, you got 30 drunks off the road.
But does it take 27 cops to man a single check point?