Convention-week detours eyed

The major alternative routes for traffic detoured from Interstate 93 during the Democratic National Convention will probably be Route 128 and the Ted Williams Tunnel, shifts that would pack tens of thousands of additional cars onto those roads.

Secondary roads such as Routes 60, 99, and 1A north of the city are expected to be quickly overwhelmed, too, as motorists search for alternatives.

"People should understand their evening commute will not be a smooth one and consider leaving their cars at home, taking the T, or finding other ways to get into the city," said Tom Tinlin, deputy commissioner at the Boston Transportation Department.

Jon Carlisle, spokesman for state Transportation Secretary Daniel Grabauskas, said the state is still working with the Secret Service and the city to develop a comprehensive detour plan. But he said it is reasonable to assume that Route 128 and the Ted Williams Tunnel will be major alternative routes.

Local officials are concerned that without I-93, the region's main artery, other roads could be gridlocked. Malden Police Chief Ken Coye, said the impact on his city, where officers patrol a crowded Route 60, could be great.

"It would almost be like Greater Boston before I-93 was built," said Coye, whose city is also home to Malden Station, a transfer point for commuter rail passengers forced to switch to the Orange Line, because of the planned closure of North Station during the convention.

The concerns underscore the difficulty of rerouting traffic from a high-volume interstate that cuts through a city bordered on one side by the Atlantic: There are very few places to send tens of thousands of cars. The problems also illustrate how quickly the city has come to depend on the newly opened I-93 tunnel, which carries about 30,000 vehicles each weekday evening.

It's not clear how lengthy a stretch of I-93 will be closed for the four nights of the convention. But even if a shorter expanse of the road is closed, traffic analysts said, officials would probably encourage motorists to drive around the city.

Southbound drivers on I-93 would then pick up Route 128 at the interchange in Woburn, the most dangerous and heavily travelled cloverleaf in the state. I-93 northbound drivers would get on Route 128 south of the city in Canton. Drivers coming north from the South Shore on Route 3 or those getting on I-93 northbound closer to the city will probably take the Massachusetts Turnpike west to reach Route 128 at the Weston tolls.

A state transportation official who asked to remain anonymous said that both the Sumner and Callahan Tunnels could also be closed, forcing more traffic to use the turnpike and the Ted Williams Tunnel.

As a result of an expected increase in Pike traffic, State Police Colonel Thomas J. Foley suggested yesterday that turnpike officials may suspend tolls to keep traffic flowing.

"I don't have the authority to do that, but I think that might be something that the turnpike might consider at some point," Foley said.

Pike officials said the issue has never been raised with them.

Despite widespread fears about traffic nightmares during the Democratic gathering, there is some precedent for the closure of I-93. Last year, just before the northbound Big Dig tunnel opened, officials limited I-93 north to a single lane while encouraging drivers to use the Pike and Route 128. For the most part, the detour worked.

The Route 128 detour, under ideal conditions, would not add significant time to a driver's commute. According to Jeff Larson at SmartRoutes, which generates local traffic reports, southbound traffic on I-93 can go from the Route 128 and I-93 interchange in Woburn to the Braintree split in 33 to 35 minutes. Using 128 would add between 10 to 12 minutes to that trip, he said.

But that's based on speed-limit conditions, and drivers cannot count on that, because of anticipated increase in volume on the Pike and Route 128 during the detour. Also, heavy nighttime truck traffic could add to delays.

MassHighway officials said an average of 18,554 vehicles travel I-93 northbound from 5 p.m. to midnight on weekdays, while 12,544 vehicles travel 93 south during those hours.

"I don't know where the detour is going to be, but I think it's logical to say that through-traffic going through the city should go around the city," Larson said.

Another detour used in the past when I-93 access was limited involved rerouting northbound traffic through the Ted Williams Tunnel and over to Route 1A in East Boston, where traffic can pick up Route 1 northbound.

But that narrow roadway is already under some stress. Since Route 1A was directly connected last year to the Ted Williams Tunnel, the number of cars on it everyday has jumped: The latest figures provided by state highway officials show approximately 50,000 vehicles per day using Route 1A north of Logan Airport, 20,000 more than it is designed to carry.

This route and others like it, including Routes 28, 99, 16, and 60, are more likely to become clogged, as thousands of drivers attempt to travel on roads that long ago reached their limits.

These potential problems will be dealt with by a small army of State Police. Foley said nearly half of all troopers in the state, between 1,200 and 1,300, will be in and around Boston during the convention.

"It is going to take a significant amount of people to manage that roadway," he said, referring to the closure and detours around I-93. "I think we all see that on a daily basis. One accident out there, and the traffic jams. Certainly we are going to strive to make this as painless as possible for everybody out there, but we're fully aware of what this is going to do to disrupt people's lives."