The World Naked Bike Ride is a protest, first and foremost, against our dependence on oil and for cyclist safety on the road - so don't expect much sympathy from the riders for the cars that get stuck in its wake.

Every year Portland drivers get stuck for more than an hour on the sidelines of the 10,000-person naked bike ride, as police shut down streets to let the nude masses pass. In the past, the fury has led to physical and verbal confrontations, with the occasional driver pushing through to cross past.

Organizers of the World Naked Bike Ride don't release the route publicly. The fear is that people will line the sidewalks, break out the camp chairs and spill into the streets. That could cause a further bottleneck for the ride, and many are concerned about the potential for lewd behavior or unwanted physical contact.

"Bad things happen when people know where the ride will go," Carl Larson, a longtime route planner for the event, explained. "I would love it if we could release the route ... but unfortunately it just becomes a safety issue."

The ride used to go through Old Town so consistently, that in 2014 people filed out of bars to watch it go by, he said. Things got so out of hand that police had to clear out the streets so the cyclists could pass. Some riders reported getting groped by spectators.

"That's pretty scary for us," Larson said.

Ever since the World Naked Bike Ride joined forces with Portland Police, the route has been planned to move as swiftly and safely as possible. About 40 officers lead the protest through Portland, blocking off streets to let the mass through.

Only a few officials in the Portland Police Bureau know the route. They share it with liaisons in Portland Fire & Rescue and TriMet for emergency purposes and possible re-routing of public transportation.

Bret Barnum, the special events coordinator for the Portland Police Bureau, apologized to the people who get stuck in the traffic, but agreed that releasing the route could endanger the riders.

"There's a lot of concern about participant safety," he said. "We don't want to create an event where somebody is harassed."

With all parties holding firm, there's little chance the route will ever go public. But while you can't know the exact streets to avoid, there are still some ways to try to avoid it. Take a couple pro tips, from the people who put it all together:

-The Naked Bike Ride is capped at six miles, from start to finish. As long as you're outside that radius, you'll be fine.

-The ride will never cross train tracks, due to safety and public transportation concerns.

-Several bridges are out of the equation for various reasons, including the Hawthorne Bridge, the Broadway Bridge and, most likely, the Tilikum Crossing.

-Route planners generally avoid steep hills, which takes out most of west Portland.

-The ride is careful to stay away from freeway ramps.

-Wide streets that go through business corridors are popular, balancing visibility with the practicality of funneling 10,000 people through.

Of course, the only surefire way to avoid the World Naked Bike Ride is to stay off the streets where and while it's happening. The 2016 ride will start at 9 p.m. on Saturday, June 25, at Mt. Scott Park in southeast Portland.

You've been warned.

--Jamie Hale | jhale@oregonian.com | @HaleJamesB