When Virginia lawmakers return in January to Richmond to tackle another legislative agenda, they’ll wrestle with weighty priorities that include the budget, education and transportation — and when it is safe to open one’s car door near moving traffic.

The proposal is just one of several bills filed by legislators for the upcoming 30-day session. Nearly 400 proposed measures were prefiled for the 2013 General Assembly, which begins Jan. 9.

Quirky legislation is nothing new in state legislatures, and Virginia has had its share over the years. Many of the offerings start with a particular complaint from a group or constituent, said Bob Holsworth, a longtime Richmond political observer and former Virginia Commonwealth University professor.

“It’s usually something that happened in their community and they’re looking for a statewide answer to it,” Holsworth said. “There’s almost always a story behind every bill.”

House Speaker William J. Howell (R-Stafford), heading into his 26th General Assembly, chuckles at such legislation.

“I still kind of keep a little file of what I call ‘the stupidest bills,’ ” he said. “It’s the process. We’re all part-time legislators who are back home in the community 10 months out of the year. We run into constituents who say they have a particular problem and we say, ‘I can fix that!’ ”

Del. Joseph D. Morrissey (D-Richmond) is bringing the War on Cigarette Butts back to the legislature. Under a bill being reintroduced this session, the butts would be considered litter and butt flickers would be subject to criminal punishment, a fine and community service.

Morrissey was out of the country and unavailable for comment, but a legislative aide pointed to statistics citing cigarette butts as “the most littered item in America” as part of his reasoning for the legislation.

In the Senate, J. Chapman “Chap” Petersen (D-Fairfax) has proposed banning people from opening a car door near moving traffic “until it is reasonably safe to do so.” The bill also would forbid a person from keeping the car door open “for longer than is reasonably necessary to load or unload passengers.” The offense would be punishable by a fine of up to $100. It would not apply to law enforcement officers, school guards, firefighters or members of a rescue squad performing their duties.

Unlike controversial measures that can raise a lawmaker’s profile or further a political agenda, quirkier bills are a type of constituent service — a way to say to a voter, “This is important to me.” Oftentimes, they aren’t part of a larger legislative agenda, and don’t get very far.

“Some of them have surprised me that they’ve gotten out of committee,” Howell said. “Usually, the committees will take care of them.”

Despite his amusement, Howell said he sympathizes with some of his fellow lawmakers.

“Sometimes, in their own mind, they think it’s a good bill,” he said. “There are ones that might sound a little wacky, but to a lot of people, they have some merit.”

House Bill 1375 may turn out to be such a case during this General Assembly session. The legislation would require a business that is not a gas station or bank with a restroom to allow customers with written proof of certain medical conditions to use that facility or be subject to a fine of up to $100.

The measure was proposed by Del. K. Rob Krupicka (D-Alexandria), a newcomer to the legislature who won a special election in September.

Krupicka said he plans to introduce legislation this session related to education and transportation, but he also wanted to make this bill a priority. It is particularly aimed at helping people with colitis and Crohn’s disease , a chronic inflammation of the bowels with symptoms that often require immediate access to a restroom.

“I wanted to get this one out early because the family members and support groups . . . wanted time to start talking to legislators about their situations,” Krupicka said. “If you’re not aware of this disease, people may laugh it off.”

Krupicka became aware of the issue after a high school student in his district brought it to his attention, but similar legislation has been passed in 13 other states. He hopes raising the issue will educate fellow lawmakers about the illness.

“Not every piece of legislation has to be enormous, but should have an impact on people’s lives,” he said.