Somerville Police handed out more than 40 tickets to bicyclists caught breezing through red lights, cruising on sidewalks, and riding against traffic on two recent enforcement days, the department said.
The crackdown is expected to continue, said Sergeant Sean Sheehan.
Three more days of targeted enforcement are planned, Sheehan said, but he wouldn't give away the dates.
"Generally what the department wants to do is to get some feedback and see how its working, if people are following the rules a little more," Sheehan said.
The fines are for $20 for most infractions, which were mostly for cyclists who ran red lights, he said.