Extending the hours for parking meter enforcement in downtown Lawrence is worth considering, and not just because it could raise more money for city coffers.

The purpose of meters at a number of downtown locations isn’t just to collect money from the parking public. It’s also to encourage turnover in prime parking places. Although some downtown business owners object to the meters, they need to recognize that the system actually is designed to increase the odds that people will be able to find parking places near the businesses they want to patronize.

Lawrence city commissioners are considering the idea of extending the hours for parking meter enforcement and perhaps using the increased revenue to finance increased police patrols downtown. People parking at metered spaces now need to pay for parking between 9:30 a.m. and 5 p.m. Monday through Saturday. The rest of the time it’s free.

That means that when people come downtown to shop at stores that keep later hours, eat an evening meal or enjoy an entertainment venue, they don’t have to pay the meter, but it also means they will have little chance to find a parking place. After 5 p.m. or on Sundays, there is nothing to keep people who live or work downtown or are staying at a downtown hotel from parking their cars in prime spaces for extended periods, perhaps even overnight. That makes those spaces unavailable to people who may want park for an hour or two to shop or eat.

Extending enforcement of parking meters until 9 p.m. or 10 p.m. seven days a week would discourage long-term parking just as it does during traditional business hours.

As some merchants noted, after 5 p.m. has become prime time in downtown Lawrence. It makes no sense to quit charging for parking when the most people are looking for spaces.

Some downtown business people advocate free parking because their competitors in other parts of Lawrence and nearby cities can provide that amenity. But those businesses in Lawrence and elsewhere don’t share the parking limitations of downtown. Ironically, the advantage of “free parking” is largely a matter of perception. There usually are plenty of free parking spaces available in lots and parking garages near Massachusetts Street, but even though the distance from those lots to a downtown destination is no greater than the distance across a suburban parking lot, people perceive it as less convenient.

It’s a hard perception to fight, but removing parking meters from Massachusetts Street would only exacerbate the problem.

City officials will need to make sure that extending parking meter enforcement will generate more than enough money to offset the cost of that enforcement. But if the move seems cost-effective and especially if it provides a way to fund more police presence in Lawrence at night, it seems like a good move.