Here's the deal ... T-Swift's up in Toronto for a few "Eras" tour shows -- and, yesterday, video surfaced of the pop star and her team getting Justin Trudeau-level treatment in the city, with cops leading her down an empty highway on the way to her show.

The move pissed off a lot of people in the city ... who posted videos to social media calling Taylor out for totally shutting down the highway and causing traffic jams -- but, cops tell us that isn't exactly the case.

A rep for the Toronto Police Department tells TMZ ... the police escort is part of the overall security plan in the city -- 'cause she has a large and active following, and this protection is in the best interest of public safety.

Plus, TPD didn't close down the entire highway completely, we're told ... but, instead officials did "rolling closures" which -- as we understand them -- means closing down the highway by sections as the vehicles passed.

Basically, people could drive on the freeway ... just not at the same time or speed as Swift. If you watch the videos closely, there seem to be cars following her little bubble of protection at a respectful distance.

Taylor made it to Rogers Centre -- home of the Toronto Blue Jays and Taylor Swift for the next few days ... which, BTW, has a hotel attached to it. Probably a bit of a safety concern to stay there with all her fans milling about, we'd guess.

As you know, Taylor put on a great performance for her fans in America's neighbor to the North ... gyrating onstage in a very sexy way days after visiting Travis Kelce.