Concerns over traffic prompted the Portland Planning Board to postpone a vote Tuesday night on a new master development plan for Thompson’s Point – a highly visible former industrial area that is being remade into an arts and entertainment center.

The plan still calls for an arena for the Maine Red Claws, a circus school, a sports medicine lab, a hotel and restaurants as well as office, event and concert space. But it would expand by 2.5 acres, freeing up more development opportunities, which would likely lead to more traffic.

“With me, one of the keys is traffic coming in and out of there,” said board member Timothy Dean.

Other board members wanted to see more three-dimensional renderings and more details for an area zoned for 120-foot-tall buildings, including residences.

The board will take up the plan again on Feb. 26.

Thompson’s Point is a roughly 30-acre parcel near the Portland Transportation Center and Interstate 295. It’s across the Fore River from the Portland International Jetport.

The master plan lays out the general development concepts, including an arena for the Maine Red Claws. Planning Board Chairman Stuart O’Brien said individual site plans will still need the board’s approval.

Because the new master plan calls for a more intense use of the site, there would be more traffic than originally predicted.

Randy Dunton, a traffic consultant for the project who is with Gorrill Palmer Consulting Engineers, tried unsuccessfully to persuade the board to address traffic issues with each site plan.

Dunton noted the project currently has a traffic permit from the Maine Department of Transportation that allows for 1,091 trips in the evening peak hours. The new development could increase that number to 1,314 trips, prompting the need for a new permit, he said.

Dunton said the permit prohibits events from starting between 4 and 7 p.m. and requires the development to have a traffic demand manager, whose job it will be to reduce traffic.

Also, events with 2,500 people or more require traffic officers, said Dunton, who estimated that there would be one car for every 3½ people.

Meanwhile, improvements to roadways leading to the point are also being undertaken, including widening of I-295 off-ramps and new signals.

Current plans call for a three-lane road leading into the site. Two lanes could be used to get traffic onto the point before a show and two lanes could be used for exiting traffic after the show.

Board members wanted more time to review the traffic impacts.

The new plan calls for up to 120 residential condominiums, additional building space, a wider variety of uses and an increase in traffic. It also calls for renovating and re-using four existing buildings – some of which had served a railroad – that had been originally slated for demolition.

Randy Billings can be contacted at 791-6346 or at: rbillings@pressherald.com

Twitter: @randybillings