State highway engineers have begun a new monitoring regime on the Lagoon Pond drawbridge after it apparently shifted on its pilings and would not close, blocking traffic for several hours over the busy Memorial Day weekend.

The bridge was stuck in the open position for about three and a half hours from 5 p.m. on Sunday, forcing traffic to detour along Barnes Road. The malfunction caused traffic jams and delays, and created a substantial backup at the blinker light intersection in Oak Bluffs where many cars were detoured.

Donald Pettey, a district assistant maintenance engineer for Mass Highway, said a survey crew arrived on the Island yesterday to begin work monitoring movement of the old bridge. He also confirmed it had been necessary to remove steel from the bridge to make it close on Sunday night.

It was the first time in about two years that steel had been cut from the bridge to make it close. But movement has been a longstanding problem. Over 10 or 12 years, Mr. Pettey said, about six inches in total had been cut off the moveable span of the bridge when it refused to close due to either movement of the bridge foundations or expansion of the metal in hot weather.

Extra cables also have been installed to try to anchor it more securely.

Mr. Pettey said there now would be continuing monitoring of the bridge for movement both laterally and longitudinally, and a crew would remain on-Island through the summer in order to more quickly fix potential future problems of the same kind.

He acknowledged concern that pile-driving work on a temporary replacement bridge could exacerbate the stability problems of the old one.

“The survey crew will establish better survey points which will be monitored as construction proceeds, to avoid problems,” he said.

Though Mr. Pettey said it was not proven that work on the new bridge was accelerating the instability of the old one, Bob Maciel, the longtime bridge tender, has no doubt about it.

“I can’t tell you how bad the vibration has been during the construction work,” he said, adding:

“There’s no doubt with all the vibration, it’s getting worse.” He continued:

“Depending on whether the tide is running in or out, it moves the bridge in that direction. The problem on Sunday was that I put it up and it moved and when I went to put it down again it wouldn’t close. It had slanted over with the tide and was out of alignment.

“It’s so messed up it’s pathetic.

“Generally, when I get called now, it’s because it’s so shaky, I don’t go up there until five minutes before the boat comes.”

Mr. Maciel also expressed concern about continued use of the bridge by large trucks. The weight of vehicles crossing the bridge now is restricted to a maximum of 24 tons (actually 12, 15 and 24, depending on the number of axles on the truck).

But Mr. Maciel said the limits are not being enforced.

“Some big trucks still come over, and when they do that also loosens up the bridge. Then the next time I open it, I have a problem getting it back down again,” he said, adding:

“It’s very important these big trucks abide by the signage, but not all of them do. The police don’t care, they say they can’t sit there and watch every truck that goes over the bridge, but somebody should be doing it.”

The Lagoon Pond bridge reconstruction has been a continuing controversy for almost 20 years. It was first mooted in late 1989, at a cost of about $4 million.

“The latest cost estimate,” said bridge committee chairman Melinda Loberg, “is about $9.2 million for the temporary bridge, and the cost of the permanent bridge now is up to $34 million, based on inflation in materials in 2013 [the scheduled completion date].” She also said:

“The timetable for this whole project, the idea that we needed two bridges, was dictated mostly by the fact that by the time they really started to pay attention to this bridge it was in such a state of disrepair that they didn’t have time to build a whole new bridge, so they had to put in a temporary one.

“That’s what drove the whole two-bridge solution.”

And the timetable continues to change.

Ms. Loberg said a meeting to be held today with state highways officials on the Island would likely see the completion date for the temporary bridge pushed back.

“The temporary bridge project is delayed right now,” she said.

“They switched the schedule last fall. Ordinarily they would have been able to do work in the water November, December and January. But they were unable to do that because they did not have the total design complete. So they switched it and did the land-based preparation you’ve seen — the sheet piling, the building of retaining walls, putting in fill, moving wetlands and so on.

“But the problem still remains that the final design for the moveable part of the temporary bridge has not yet been approved by Mass Highway.”

That could mean they would be unable to begin driving piles in the water, as planned, by June 1.

“We expected them to be ready to do that, but my guess now is they won’t be, because they can’t drive piles until they know for sure the final design,” she said. She continued:

“We really didn’t like the idea of pile driving in the summer. But on the other hand we also don’t want to hold up construction. Our goal is to try to ensure that the bridge is not declared impassable before the temporary bridge is in place.

“That’s the reason the heavier trucks have been asked to go around for the past year and a half — the condition of the bridge.

“It’s a voluntary thing. The Mass Highway department has not officially downgraded the load limits on the bridge. Their inspection results show it has not yet deteriorated to that point, but when the heaviest trucks go over, it really shakes the bridge.

“They should be opening the temporary bridge, supposedly, in the fall, but it doesn’t look like it’s going to make that deadline. More likely it will be next spring.

“But we’ll know more definitively when the state releases its revised schedule. I’m just holding my breath and waiting.”

She is not the only one.

Lisa Rusche, owner of the Clark House near the intersection of State Road and Edgartown-Vineyard Haven Road in Vineyard Haven, has had to put up with the noise of all those extra heavy trucks since the bridge was limited.

She no doubt spoke for many people who live along the detour route while the bridge is under construction, when she stood up at the most recent meeting of the Steamship Authority governors to complain about the SSA’s role in disturbing her peace, and that of her guests, particularly early in the morning.

She suggested SSA officials eliminate the 6 a.m. run from Woods Hole, or, failing that, try to direct more trucks through Oak Bluffs.

“Big 18-wheelers just chug on up the road. There have been 9,796 trucks, year to date, almost all of them come this way, shifting gears when they come up the hill,” she told the Gazette later.

She appreciated the explanation given her at the boat line meeting that those trucks could not go later, if they were to make their deliveries on time.

“But what really gets me is that they can’t even look at their own bill of lading, at least in the summertime and see which is an Oak Bluffs truck, and then put it on an Oak Bluffs boat,” she said.

“It shouldn’t be that difficult; it’s all computerized these days.”