Among the many challenges for the city in past years has been the so-called 'mall crawl', which some people want to revive this weekend.

In 1990, more than 40,000 packed the Pearl Street Mall, causing damage and forcing police to break out their riot gear.

"It's my first year here, so, I hear Halloween is the craziest holiday in Boulder," CU freshman Kristin Gorski said.

Boulder police do not want history to repeat itself, so they will be out in force Saturday. BPD plans to have about 40 officers on duty on Pearl Street, in addition to extra patrols elsewhere in town.

"So, we're preparing for a busy weekend and the possibility of large crowds, but we're also hoping for a quiet night," Boulder police spokeswoman Sarah Huntley said Friday night.

Other factors for police this weekend include the University of Colorado's homecoming game, daylight saving time and Boulder's annual naked pumpkin run, in which people run completely naked through the streets with pumpkins over their heads.

"It's usually old people though," CU freshman Hayley Thomas chuckled. "Old people want to get naked, so, they take their clothes off and put a pumpkin on their heads."

It is against the law in Boulder to run completely naked on public streets. That's why Hapa Sushi is offering to give participants panties. The restaurant wants to help keep runners from getting arrested and possibly registered as sex offenders.

"Pearl Street Mall, there's a lot of business owners on the mall to keep Boulder safe, weird, fun," Hapa Sushi General Manager Troy Kilgore said.

Several business owners on the mall don't want to see a revival of another tradition, the 'mall crawl.' In the past, it has involved thousands of masked people partying on Pearl Street. Some have broken windows and damaged businesses in other ways.

"We hope not. There has been a Facebook campaign, and some media attention to the possibility of restarting that," Huntley said.

The message from Boulder police is, go ahead and have fun, just don't break the law.

As for daylight saving time, police are asking bars not to stay open the extra hour, to minimize the risk of alcohol fueling crime.

Some bars have voluntarily agreed to comply with the request.

Denver police say they are not asking bars and restaurants to close when the time change occurs. But starting Friday night, they are stepping up DUI saturation patrols to keep drunk drivers off the roads.