Shoppers browse along Massachusetts Street.

If a group of downtown merchants has its way, there soon may be a new twist to the parking meter system on Massachusetts Street.

Representatives from about 40 different downtown businesses have signed a petition urging the Lawrence City Commission to designate four parking meters in each block — from Sixth to 11th on Massachusetts — as 15-minute meters.

“The current system is just deterring quick business coming in from off the street,” said Chris Lowery, manager of Meritrust Credit Union’s downtown branch.

He said customers almost daily tell him of having to drive around the block multiple times to find a place to park to quickly use the credit union’s ATM. He said restaurants complain of losing out on carry-out business, coffee shops miss out on some sales, and that several other businesses have services that would attract in-and-out customers.

Now, city commissioners have to be convinced.

Commissioners in July heard a similar proposal from Downtown Lawrence Inc., but rejected it over concerns that it would create confusion and eliminate too many two-hour parking meters.

“I still have the same concerns,” said City Commissioner Mike Amyx, who owns a downtown barber shop. “I think it has the potential to aggravate potential shoppers and people who patronize downtown.”

Lowery thinks the special meters could be clearly marked — perhaps painted a different color — to alert motorists that they’re not the standard two-hour meters.

The change to the meter system would come after other large-scale changes were implemented this summer. In August, the city increased the rates it charges at various parking meters, and also increased the fine for overtime parking.

Mayor Rob Chestnut said he wanted to see if those changes were causing motorists to vacate their parking spaces on Massachusetts more quickly than in the past.

“I think the new fines and fees will make people think more about whether they really want to park on Massachusetts or in a more cost-effective lot just off Massachusetts,” Chestnut said.

Commissioners meet at 6:35 p.m. Tuesday at City Hall.