Going north into Maine on Interstate 295 from Topsham to Gardiner will be the easy part this summer. Going south again will be another matter entirely.

From June 16 through at least August 30, the Maine Department of Transportation (MDOT) is closing the two southbound lanes of I-295 for the eighteen miles between Topsham and Exit 49 in Gardiner. It will give commuters, vacationers, commercial vehicles, and other travelers - some 13,500 cars and trucks a day on average - the option of heading south by looping west through Lewiston on the Maine Turnpike or taking their chances on a two-lane highway, Route 201, that meanders through a string of quiet, rural towns along the Kennebec River.

No one is happy, especially the folks who live along 201, where traffic may increase by as much as ten thousand cars a day - an average of seven cars a minute all day, every day. But if the art of successful negotiation is to leave everyone equally unhappy, then MDOT has met the standard.

"I was shocked initially," admits Richmond Town Manager Thomas Fortier. "It seemed almost unimaginable to take all that traffic off 295 at the height of tourist season and send it down 201."

Even MDOT Commissioner David Cole was leery. "When the planning team first came to me with this idea, I'll admit it got my attention," Cole allows. "The more we looked at it, though, the more it made sense."

The problem is concrete. The stretch of I-295 north of Topsham was built in 1974 using concrete slabs, the source of the distinctive ka-thunk, ka-thunk, ka-thunk travelers hear as their vehicles' tires pass over the joints between the slabs. Joyce Noel Taylor, an MDOT engineer and the assistant director of the bureau of project development, calls it "vintage concrete," both because it's old and because it has a certain aura - mostly of dust as it disintegrates.

Over the years the aggregate that was mixed with cement to make the concrete has sparked a chemical reaction that is destroying the slabs. "Basically it's causing a fracturing of the concrete," Taylor explains. "We've had fist-sized chunks coming off the surface and flying through people's windshields." Attempts to control the problem by covering the slabs with asphalt or a bonding agent have been unsuccessful.

Taylor's favorite show-and-tell is a table scattered with cores taken from the wheel paths in the Interstate's travel lane. "They don't hold together, " she points out, waving at the shattered samples. "The cores come out in pieces."

The situation has been recognized for years, Taylor says, noting that the Federal Highway Administration "has been pushing us for as long as I can remember to do something about the concrete." Tests late last year brought matters to a head. "The more we looked, the more nervous we became," she says.

Some sections of highway have deteriorated so badly that Taylor has raised the possibility that the Interstate would have to be closed even if reconstruction wasn't on the agenda. Modern concrete doesn't have the same problem because fly ash is added to the mix to counter the reaction, she adds.

David Cole says he knew the decision to shut down I-295 southbound would spark controversy, but it was the most attractive option on the list. "We weighed a lot of different factors," he explains. "Safety was paramount, plus there was the fact that we could get in and get out in one [construction] season rather than stretching the project out over three seasons."

Vaughn Stinson of the Maine Tourism Association - who lives in Topsham and works in Hallowell - recalls attending the first public meeting about the project with what he thought was an excellent list of alternatives to closing one of the major tourist routes in the state. "As it turned out, they weren't so great after all," he says.

Closing down one lane at a time, Taylor says, was considered and then dismissed for both practical and safety reasons. There was the danger posed by putting a hundred or more construction workers within inches of fast-moving traffic, the inevitable traffic jams that would occur at rush hour, and the difficulty in getting police and emergency vehicles through the construction zone to reach accidents. The same arguments counted against putting two-way traffic in the northbound lanes. There was also the attraction of getting the job done in two and a half months instead of three years.

In addition, the original design of the concrete slabs posed a unique set of problems. Each slab spans both southbound lanes. Plans currently call for the top three inches of concrete to be milled off the road surface. Then a machine called a "rubblizer" will come in and, using a hydraulic metal foot, smash the remaining concrete into small pieces that can be incorporated into the new roadbed. "Our fear was that, by trying to close one lane at a time, the concrete in the travel lane would disintegrate as soon as we put the rubblizing machine to work on the other lane, because the steel reinforcing bars in the concrete cross both lanes," Taylor says.

Closing I-295's southbound lanes entirely for the massive reconstruction effort reflects both the sense of urgency MDOT has about the project and a shift in philosophy about big highway jobs. The new catch phrase is "get in and get out," shutting down an entire construction zone to traffic and using detours to reroute vehicles while contractors move in large work crews and lots of machinery without having to worry about maneuvering around thousands of cars and trucks. "It's faster and safer," Taylor says, noting that Maine records an average of five hundred to six hundred accidents each year in construction zones.

Cole says the MDOT's experience with repairs to Memorial Bridge in Augusta two years ago proved the effectiveness of this new tactic. "We did a complete closure and got the job done in three months, instead of the seven to nine months we would have needed using a partial closure approach," he explains. Since then, the same strategy has been used for projects in Bath and Woolwich. "Many states are using the same philosophy now," Cole adds, citing the experience in Ohio, Delaware, and Kentucky, among other adoptees. "There are big effects on safety, efficiency, and travelers."

"We'll be working seven days a week, extra long shifts every day, with multiple crews working on various sections of the highway," says Christian Zimmerman, president of Pike Industries, the New Hampshire-based company that won the lead contract for the thirty-million-dollar job. Zimmerman says the company is prepared to go to a 24/7 work schedule if weather causes delays. The contract contains incentives for finishing early and penalties for finishing late.

The Maine Turnpike Authority, meanwhile, anticipates raking in an additional nine hundred thousand dollars in toll revenues from travelers who opt to stay on Interstate 95 southbound. The authority has announced it will give three thousand E-Z Pass transponders to temporary commuters. They can avoid paying the $26.25 transponder fee by returning the devices by October 15.

None of that was much consolation to the residents of Richmond, Bowdoinham, Bowdoin, and Topsham when they heard that MDOT planned to route most of I-295 past their doorsteps. They turned out in force at public meetings to discuss and criticize the proposal, and MDOT significantly altered its plans as a result. "Originally we had an image of traffic on 201 going right along at a steady pace - fifty, fifty-five miles an hour," Taylor explains. Now, she says, "We want the highway to look and feel like a construction zone."

Speed limits will be dropped by at least five miles an hour for the length of the detour. Traffic lights are being installed at the intersection with Route 197 in Richmond. Radar signs will warn speeders, and law enforcement agencies have promised stepped-up patrols along the road.

In addition, Cole says, the Maine State Police will be conducting special truck stops for safety inspections and logbook checks on Route 201 - but not on the corresponding section of the Maine Turnpike. The plan, he says, is to "encourage" truckers to use the turnpike rather than steering their big rigs down 201.

Taylor describes Route 201 as one of the best roads in the state, and neither she nor Cole anticipate that it will need much, if any, extra repair work when the detour is over. "Route 201 was built to handle this volume of traffic," she notes. She expects traffic density will be similar to that on Route 196 between Topsham and Lewiston or Route 1 in the midcoast region.

"I think residents are gradually coming around to the idea," says Richmond's Fortier. "I hear people saying that 201 used to be the main road to Gardiner before I-295 was built. And I think MDOT's been acting appropriately, meeting with our fire and rescue people and listening to people's concerns."

Fortier says town selectmen might ban yard sales along Route 201 for the duration of the detour. He also notes that the town's fire and rescue department will be responsible for responding to any accidents or other emergencies. "We anticipate some increased costs because of that," he says. "We're still negotiating with the state about reimbursement."

Kathy Durgin-Leighton, town manager in Bowdoinham, notes that her town doesn't have many residents who actually live on 201. Her main concern is the increase in traffic she expects to see on other town roads as local people try to find ways to avoid Route 201. "People are going to be using Route 24, which is in horrible shape," she predicts. "I believe it'll become a major route for people going to Bath Iron Works."

Durgin-Leighton says town officials are taking before and after photographs of Route 24 to document any extra wear and tear. "We've alerted Commissioner Cole to our concerns," she says. "The MDOT is putting traffic counters on the road to get some numbers on usage."

Representative Seth Berry, a Democrat whose district spans the length of the detour route, says he is especially worried about the many driveways and intersections along the road. "A lot of local folks are very concerned about the safety impacts," he says. "It all depends on how the details are done."

But Berry also sees a potential upside to the situation in the increased exposure that part of the state will get during high tourist season. "I would definitely encourage people who are trying to save time to take the turnpike," he says, "but at the same time, as long as everyone is careful, I would encourage travelers to try out some of the local attractions, such as Swan Island in Richmond."

Whatever happens this summer may only be the first act of an ongoing production. The northbound lanes of I-295 have the same disintegrating concrete, although the MDOT currently lacks the money to do anything about it. Taylor says the southbound lanes are being rebuilt with an eye toward accommodating traffic in both directions, but she doesn't immediately dismiss the possibility that the residents of the towns along Route 201 might face a similar summer in the near future.

"It's obvious the state is doing all it can to make this as painless as possible," Fortier adds. "Of course, those residents who have to endure the traffic might have a different opinion."