A cyclist cruises fearlessly along Mass. Ave. behind Widener Library yesterday. Over the past month, the Cambridge Police Department has issued 100 tickets for bicycle infractions.

Nighttime bikers, beware—you might be slapped with a $20 ticket.

Over the past month, the Cambridge Police Department (CPD) has handed out about 100 tickets for bicycle infractions, which include riding without a light after dark, riding on sidewalks and running red lights, according to a CPD spokesperson.

“The city has a bicycle committee and it has had complaints about students riding without lights,” said CPD officer Buckowe Yam. “We gave out lights and then eventually it came to the ticketing process.”

The increased police enforcement of these laws comes in the wake of a much longer campaign by the city of Cambridge to promote bicycle safety.

“It’s not a change in policy, it’s just the city is trying to get people to use lights as required by the law,” said Cara Seiderman, Cambidge’s transportation program manager.

Bicycle safety is a major concern—especially in Cambridge. The city released a report last month stating that “nearly half of all cycling deaths nationally involve cyclists riding at night without lights, although only 3 percent of biking occurs after dark.”

According to the Massachusetts Bicycle Coalition, a non-profit group promoting bike safety, a Boston-area study found that only 15 percent of cyclists were observed using lights.

Despite the threat of fines, students don’t seem eager to comply with the law.

“I don’t usually see people with lights on the way home,” said Evan R. Calvert ’07, a lacrosse player who bikes to practice and often gets back to the yard after dark. “I don’t have a light, but I thought about getting a reflector vest.”

But even reflector lights and vests are not enough to avoid a ticket, according to CPD, because they are only visible with a headlight shining on them.

Massachusetts law requires cyclists to use a white front light both 30 minutes before sunset and 30 minutes after sunrise. With daylight-saving time over, bicyclists are required to use lights after 5:15 p.m., according to CPD.

Cambridge has publicized an ongoing program called “Be Bright-Use a Light” to encourage residents to use lights after dark.

Last month, CPD officers often gave out free lights and local bicycle shops gave discounts on lights.

Many of these shops are still giving a 10 percent discount on bike lights to anyone who brings in a citation, a newspaper article or a copy of the “Be Bright-Use a Light” program information, available online at the city of Cambridge website (www.cambridgema.gov).