Tracing one root of I-495, Pike woes

Rare cedars limit changes to ramps

White cedar trees are mucking up the morning commute at the interchange of Interstate 495 and the Mass. Pike.

Drivers who regularly use the interchange on the Hopkinton-Westborough border know that moving from one highway to the other can be agonizingly slow during rush hour. Sometimes, cars stack up for miles, even clogging local surface streets, just to get from one thoroughfare to the other.

"The queue extends all the way back to Route 9 because the interchange of I-495 and the Mass. Pike is a bottleneck," said Westborough Town Planner Jim Robbins. "It definitely happens on Fridays and it could happen on any other day."

In addition to frustrating motorists, the congestion stymies local commerce, said Paul Matthews, executive director of Westborough-based Arc of Innovation, a nonprofit group promoting economic development along I-495. Businesses in Boston's far western suburbs need easy access to the city, not gridlock, he said. "You don't know if it's going to take you an hour to get to Boston or an hour and a half," said Matthews.

But even as transportation officials predict more congestion in the future, they say little can be done to expand the interchange. The problem, they say, is that it sits smack in the middle of the Cedar Swamp, a 1,650-acre protected wetland populated by the rare Atlantic white cedar tree.

The swamp is ecologically important enough to be listed as one of 29 so-called "Areas of Critical Environmental Concern" in Massachusetts, said Elizabeth Sorenson, director of the state Department of Conservation and Recreation program that oversees the fragile areas.

The designation technically doesn't prohibit state agencies from expanding the interchange, but it adds another level of protection beyond the typical rules that safeguard wetlands, said Sorenson. "The idea is that people need to pay more attention to these projects than they would otherwise," she said.

In practice, however, that extra layer of protection is a near-insurmountable hurdle, say others, including the Arc of Innovation's executive director.

"It's a huge issue," Matthews said. "There is a whole range of regulations on the Areas of Critical Environmental Concern. The easiest option would be to make the interchange wider, but that's not really an option in this case."

Adam Hurtubise, spokesman for the state Highway Department, which operates I-495, agreed.

"The wetlands issue is the biggest barrier to the widening of that interchange," he said. "Any significant alteration to the alignment of the ramps would impact wetlands to a great extent."

The interchange can handle around 120,000 vehicle trips a day, said Mac Daniel, spokesman for the Massachusetts Turnpike Authority. In 2005, the average weekday traffic volume there was around 105,000 vehicle trips, Daniel said. Pike officials estimate that traffic will increase to 114,000 trips in 2010, when the interchange will be at 95 percent capacity.

To handle the expected increase in traffic, the Turnpike Authority is finishing a $7 million project to add a second lane to the single-lane ramps leading from I-495 to the Pike, said Daniel. In 2003, a second lane was added to the Pike's eastbound off-ramp. Both projects stayed within the interchange's current footprint and didn't affect the surrounding wetlands, he said.

The extra lanes are expected to help, but not solve, the congestion problem, said Daniel. They're also likely the last changes that will be made to the Pike's portion of the interchange in the near future. The authority has no intention of expanding the toll plaza, he said.

The best way to cut down on congestion, said Daniel, is to increase the use of Fast Lane transponders, which allow drivers to pay tolls more quickly. "That would be the easier and more environmentally conscious solution," he said.

The jammed interchange is another example of the region's population and workforce outpacing its infrastructure, said Jim Gallagher, transportation planner at the Metropolitan Area Planning Council. The best way to cut down on congestion, he said, would be to steer vehicles away from the interchange altogether by offering more public transportation and promoting development that mixes residences and workplaces, limiting the need for highway commutes.

While admitting those changes wouldn't happen overnight, Gallagher said the country's economic woes are already making them look more attractive.

"Given the changes in the price of gas, I don't think it's unrealistic to think we might actually reduce the amount of people who go through there."