Taylor Swift is no stranger to the fact she draws a crowd ... making sure her team met with local cops before Jack Antonoff's wedding to prep for the crush of fans showing up to catch a glimpse of their favorite singer.
Beach Haven Police Chief James Markoski tells TMZ ... security for the singer and her producer pal met with the department 2 weeks before the weekend wedding, and Jack's wedding planner paid for 3 additional officers to be on duty during the event.
We're told 2 viewing areas were set up for fans outside the Long Beach Island bash in New Jersey -- cops also shut down 3 intersections to prevent cars from getting near the folks in the designated areas, hoping to get a peek of the celebs.
For those unaware, a fishing competition and a block party were going down in the area at the same time ... but we're told there were no arrests, tickets, or major injuries that went down during all the ruckus.
As for the swarm of fans, Markoski tells us they stuck around for nearly 12 hours, showing up around 2 PM and getting out of there after Taylor finally left the wedding around 1:30 AM.
Some locals were a bit irked when streets were impassible during the rehearsal dinner the night before thanks to Taylor's fans. The police chief says he was expecting "much worse" on the big day ... but adds, "I couldn't believe how calm it was." Way to go, swifties!