Matt Evans is 20 years old. Young enough to expect -- and accept -- that he can't smoke in class, at the student union or even in restaurants.

But campus sidewalks?

"Man, give us some freedom," the University of Minnesota junior said.

The U is studying whether it might ban smoking -- inside and out. Over the years, many colleges and universities have outlawed smoking indoors and around building entrances. Now, bans are going campus-wide.

The number of colleges and universities with smoke-free campuses has more than quadrupled since 2006 -- from 34 to at least 160 -- according to the Americans for Nonsmokers' Rights Foundation, a California-based lobbying group.

That list doesn't count campuses like Carleton College, which allows smoking only in designated areas outdoors and considers itself smoke-free.

"Most institutions are on this path," said Richard Davenport, president of Minnesota State University, Mankato. "If they haven't looked into it yet, they're looking at it now."

Many anti-smoking advocates are cheering the trend as a natural progression in the movement to protect people from second-hand smoke. Today's 18-year-olds grew up supporting smoke-free spaces, surveys show.

"Even five years ago, I was shocked at the thought of it [a ban]," said Katherine Morris, director of health services at the University of Minnesota, Duluth, which banished smoking last year. "More people are saying that it's just not OK to have to live in somebody else's smoke."

But some students have resisted. Some staff members worry that bans will push smokers into the streets, their cars and neighbors' yards. At least one expert warns that campus-wide bans go too far.

Dr. Michael Siegel, professor at Boston University School of Public Health, has studied and testified in favor of smoking bans in bars and restaurants and considers himself "a strong anti-smoking advocate."

But campus-wide bans "just do not make sense to me," he said. "They're not about protecting nonsmokers' health. They're about trying to change people's lifestyles. And that's a line which I don't think is appropriate to cross."

Several schools with bans report positive results: Fewer people smoking on campus and describing themselves as smokers. More people entering quit-smoking programs. "You no longer have to run the gantlet of cigarette smoke to get into a building," said Carol Grimm, director of health and wellness at Minnesota State University, Moorhead.

When the University of North Dakota began its ban in late 2007, its student newspaper, the Dakota Student, was inundated with letters and columns opposing it. Now, it's quiet, said Michael Thomas, the paper's news editor and a junior studying aviation.

"There was a lot of protest and resentment, but that happens with anything," Thomas said. "I think there's a general consensus that it's working."

Elsewhere, there's less agreement. Some students at the University of Minnesota, Duluth say that despite the no-smoking signs, they still see people light up on campus, although fewer than before the ban. Like several other schools, UMD relies on "self-enforcement," meaning students are not ticketed or fined if they're caught. The policy is meant to create a nonsmoking "culture," Morris said.

Police officers occasionally get calls or complaints, most often from staff or faculty, "but unless the smoker's in close proximity, by the time we get there, there's nothing except a butt," said Lt. Anne Peterson, director of UMD police. If she sees people smoking, she'll remind them about the policy, but "most of the time we're dealing with actual crimes."

Schools tend to take similar steps toward their bans. First, they gather research and survey students. Then they give people time to get used the idea. Next, they launch the ban, promoting smoking cessation programs along with it.

Ban is a boon for nonsmokers

The University of Minnesota is in the studying phase. Last month, Boynton Health Service and the Office of Student Affairs surveyed students, faculty and staff about their attitudes toward smoking and a possible smoking ban and will have results available soon.

Boynton's yearly surveys show that today's undergraduates have the lowest tobacco use since the data was first collected in 1992.

"This is the first group of students in our history that have really figured out the tobacco thing," said Dave Golden, Boynton's public health and marketing director.

When Kelsey Uline, a sophomore at the U's Carlson School of Management, recently walked into a Wisconsin restaurant, the smoke "kind of caught me off-guard," she said. "In a way, it felt almost rude."

She supports stricter limits on campus, although she's unsure about a total ban. "Smokers have this idea that the ban is for them -- to get them to stop smoking," she said. "Really, the ban is for us nonsmokers, so we don't have to suffer for their choices."

The University of Minnesota, Crookson campus plans to start 2009 smoke-free. Most universities within the Minnesota State College and Universities system have implemented, planned or studied all-campus smoking bans: Moorhead launched its ban in January; Winona's begins Jan. 12.

Minnesota State Mankato was supposed to be next in line.

Mankato's Davenport had advocated for a campus-wide ban after a 2005 survey showed that about 65 percent of faculty, staff and students wanted a stricter smoking policy. So the school prohibited smoking indoors and near building entrances in anticipation of a total ban.

But last month, he dropped the proposal, after hearing stories about what has happened at other smoke-free campuses.

In Moorhead, groups of students gather in the streets to smoke. When outdoor ashtrays were removed, cigarette butts piled up in neighbors' yards.

"It's just not practical," said Ryan Anderson, president of Minnesota State University, Mankato's student association, which opposed the ban. "The idea of making someone walk two or three blocks to smoke a cigarette, especially when it's cold out, that's a doomed policy in my mind."

Jenna Ross • 612-673-7168