Secret agents are patrolling the streets of Portland. Their self-assigned mission: Create safe streets.

"Agent 1," as he calls himself, has been adding new official-looking 20 mph speed limit signs along Southeast Clinton Street. The signs, reported earlier this week by WW news partner KATU-TV, read, "SPEED 20 IS PLENTY."

He's known to the public on Twitter only as aka PDX Transformation, and is assisted by fellow "Agents of Transformation." He claims he's doing the work city officials would do if only they could cut through the red tape, noting the Portland Bureau of Transportation wants to lower the speed limit to 20.

"The state won't let them," he says. "I'm just helping them."

He's not wrong.

PBOT spokesman Dylan Rivera said the city has been making changes—including what are called diverters that don't allow cars a path through the street—to move more cars off Clinton and meet the state requirements for a minimum speed limit.

"The message we agree with, but we can't condone the tactics of making their own signs," said Rivera.

The signs are illegal, he added.

Details of Agent 1's identity are unclear.

"It's best that I'm anonymous, because I can do more as such," he said. "I'm just a regular person who's lived in Portland for a number of years. I ride my bike. I walk around town. I've been somewhat involved in advocacy things."

If the details sound vague, that's because they are. Contacted by WW, he wouldn't give his name, his neighborhood, occupation or age, other than to say he was "middle-aged."

He says he's been involved in advocacy groups—again, no specifics—and that he attended Occupy Portland protests, but protesting wasn't his main interest.

"In every one of those groups you can only go so far," he says. "There are other things you can do in an ad hoc way. You know, I don't have to ask anyone's permission to do something."

The movement is called tactical urbanism and has allies in Boston and New York who've taken up the guerrilla-style cause of creating safer roads for pedestrians and bicyclists. One of the East Coasters connected him with sign maker myparkingsign.com, which made signage donations to the cause of safer streets in Portland.

Since lining the streets of Clinton last weekend, PDX Transformation has been overwhelmed with requests for more signs.

His previous projects have included putting safety cones in strategic places to make bike lanes safer. More safety cones are planned, and other bigger projects too, says Agent 1.