Cape Cod Canal Crossings: Widening the Bottleneck?

Third bridge seen as possible solution to summer traffic congestion

By JOYCE ROWLEY/ecoRI News contributor

Traffic on the Bourne Bridge, going onto the Cape or off, is brutal on summer weekends. (istock)

Traffic on the Bourne Bridge, going onto the Cape or off, is brutal on summer weekends. (istock)

As summer visitors to Cape Cod fume in gridlock 10 miles long, it may help to know that state, federal and local planners are trying to do something about it.

It’s long been a problem getting on and off the Cape on any summer weekend — so much so that locals have a tradition of standing on the bridges at the end of Labor Day weekend and waving goodbye as summer guests leave. For them, the end of the summer means being able to cross the canal freely.

But lately, even spring and fall sees its share of traffic snarls. The Sagamore and Bourne bridges turned 80 last week. Completed in 1935 under the Works Progress Administration and now owned by the Army Corps of Engineers, maintenance is an ongoing problem.

With only 10-foot-wide travel lanes and no breakdown lanes, maintenance work on either one of the bridges requires lane closures. That work can’t be done during the summer, because of a fourfold increase in traffic volumes over both bridges. Therefore, maintenance is done during “shoulder” seasons — March through May and September through November.

“Everyone is saying, ‘You have to do something about the bridges, you have to do something about the bridges,’” said Glenn Cannon, transportation planner for the Cape Cod Commission. “There’s a significant disruption of residents’ lives with lane closures.”

Cannon said there are people who don’t even try to leave the Cape on summer weekends. Bourne residents, whose town straddles the Cape Cod Canal, are now loathe to go to Town Hall on a Friday because of the long return trip through tourist traffic.

In 2013, Massachusetts Department of Transportation (MassDOT) created the private-public partnership (P3) Project SPAN that will select a private firm to finance, design, build, operate and maintain a third bridge over the canal. Last fall, Project SPAN kicked off with an industry tour, as MassDOT brought in engineers and developers from all over the country.

This year, MassDOT launched the Cape Cod Canal Transportation Study to explore the environmental issues associated with building a new bridge. A 30-member working group made up of state, federal and local stakeholders augments public-input sessions. Consulting groups Fay, Spofford & Thorndike and The Cecil Group are providing an engineering assessment of the project.

“The two projects are running concurrently,” said Bob Frey of MassDOT’s planning division. “The canal area study is one of our typical corridor planning studies. It will also be more comprehensive than the P3 study.”

Frey said the canal study is trying to address the future of the existing bridges. The P3 alternatives for either a mid-Cape bridge or a second bridge near the Sagamore are just two of an array of alternatives the study will evaluate. Having the Army Corps of Engineers in the mix changes things considerably, he said.

The Army Corps is responsible for bringing both bridges up to modern standards — 12-foot lane widths, shoulders and safe accommodations for bicycles and pedestrians. Those changes would greatly improve traffic flow, but the cost would be significant — about $320 million per bridge.

“In general, there is support for replacing existing bridges among the residents,” Cannon said. The problem, he noted, is that the bridges are structurally sound, although functionally obsolete.

“It’s a matter of perspective,” Cannon said. “From the Army Corps’ perspective, there's no justification for replacing the bridges. Their responsibility is to the shipping traffic underneath.”

He said the Cape Cod Commission has put a lot of projects on hold to see whether new bridges will be built.

“A new crossing could have major impacts to other ongoing projects,” Cannon said. “They could bypass the Belmont Circle in Bourne. A fix could alleviate the traffic problem there and decrease the cost of the project. It could become a pedestrian accommodation and improved pedestrian crossings.”

Choke points
“If you accept that the choke points are the bridges, then what are the conditions on the existing roads?” asked Ed DeWitt, executive director of the Association to Preserve Cape Cod.

By moving a single bottleneck, DeWitt believes the merge on eastbound Route 9 at Exit 6 on the Cape will still back up. “The highway and road system across Cape Cod will still have problems.”

DeWitt supports replacing the bridges through a process called “twin spanning.” He points to Connecticut as leading the way in this method of building a new bridge with modern standards next to an existing bridge, then switching the traffic over and replacing the old bridge, to minimize traffic disruption.

But the problem is more complex than just replacing bridges, DeWitt said.

“(Former) Governor (Mitt) Romney said the flyover would fix the issues,” DeWitt said, referring to the removal of a rotary and construction of an on-ramp at the foot of the Sagamore Bridge. Backups have continued to grow.

Although Cape Cod’s resident population is about 210,000, its summer population is at least double that, according to Cape Cod Chamber of Commerce data. Traffic volume on the bridges has risen in the past 40 years from 80,000 average daily trips (ADT) to 130,000 during peak season. Off-peak January ADTs more than tripled, from 20,000 in 1972 to 75,000 by 2012.

“There is an opportunity to get a good solution,” said DeWitt, voicing concerns that the industry-financed alternative was begun before the public got involved.

“I’m not sure that starting with preconceived ideas will get that result.”

DeWitt noted that there are substantial environmental issues to a central bridge as has been proposed by the state. The proposed northern terminal in Wareham lies in areas of special concern, wetlands and herring runs, he said. On the Cape, the P3 bridge would end at Joint Base Cape Cod, formerly Camp Edwards, a military base that lies over the Sagamore Lens — the largest of six groundwater lenses included in the Cape Cod Sole Source Aquifer and is the public drinking-water supply for the towns of Barnstable, Bourne, Falmouth, Mashpee, Sandwich and Yarmouth.

“It was a major accomplishment to get it protected,” DeWitt said of the largest lens. “Governor (Jane) Swift reserved and protected that area and the state monitors the military activities there.”

The memorandum of understanding between the state and the Pentagon only allows three uses on the property: water supply, habitat and compatible military training, according to Mark Begley, executive director of the Massachusetts Environmental Management Commission at the military base.

Much of the prior military practices using artillery, rockets and mortar have been banned. There was talk of eliminating the base altogether, Begley said, but at 33 square miles, it’s the only place in New England to do large-scale operations training.

“Everyone needs to have input on how to deal with the traffic while protecting the resources — whether habitat or aquifer,” Begley said. “The only way to really make progress is to have good dialogue when people have strong opinions, especially about the bridges.”

MassDOT’s Frey encouraged people to sign up for the project’s e-mail list. “There’s a long way to go with plenty of opportunity for public comment on the process.”