Under the proposal, the agency of transportation would repair or replace bridge 59, which is located just south of the intersection with Blue Brook Road, sometime in the next four or five years. Depending on the replacement plan approved by the AOT, the work could mean the installation of a temporary bridge and two seasons or more of work, or a detour around most of West Dover with a quick, four-week bridge replacement.
Although the bridge is still safe, Vermont Agency of Transportation Senior Project Manager Christopher Williams showed several structural defects that he said would eventually result in failure. He offered a photo of the underside of the road deck that showed a spot where concrete had sloughed off, leaving bare steel reinforcement. He said that eventually a hole would develop, and despite repairs, it would continue to be a problem until the deck is replaced.
The existing bridge was built in 1926, spans 35 feet, and is also 35 feet wide. The deck was widened with a concrete slab in 1978. According to AOT figures, the bridge is crossed by 4,900 vehicles per day, 6% of which are commercial trucks.
Williams said at least three replacement designs had been considered: A partial replacement of the bridge including the deck and superstructure, replacement of the entire bridge with a 55-foot span, and replacement of the bridge with a 65-foot span.
Williams said the first option is the least desirable because it doesn’t meet flood requirements, and it would be considered a short-term, 20-year replacement. At a cost of $800,000 to $1.2 million in federal and state funds, Williams said the option wasn’t cost-efficient.
The second option, replacing the bridge with a 55-foot span, would meet flood criteria and would be designed with an 80-year lifespan. But the design would require raising the grade by about a foot, which could pose visibility problems for drivers.
Williams indicated that the AOT’s preferred option was to replace the existing bridge with a 65-foot span. The project wouldn’t require raising the existing grade, and it would meet flood criteria. The cost difference between the 55-foot span and 65-foot span would be negligible, according to AOT estimates.
Williams said there were also three options for dealing with the closure of the bridge during construction. One option would be to close one lane of the bridge for work, while allowing traffic to pass on the other. Williams said that would result in a traffic bottleneck that would last for many months. “It’s like trying to make a bed while someone’s in it. We ruled it out. It would be a total mess with the volume of traffic there. You would be mad at us, and it would be for a long, long period of time.”
Installing a temporary bridge would also be an option, Williams said, but it would lengthen planning and execution of the project by years and increase costs by at least $250,000. “There would be right of way issues,” he said. “Depending on which side of the road we put the bridge, there could be utilities (sewer) issues. We can’t build a temporary bridge over utilities without moving them. This is what we call ‘scope creep,’ and we try to avoid it.”
The third option, preferred by the AOT, would be to close the bridge and detour Route 100 traffic over Coldbrook Road, Handle Road, and Tannery Road. Williams said the option would mean a quick turnaround – a total of about four weeks of construction during which the bridge would be closed. The time limit would be reinforced through contractual incentives and disincentives, he said, which have almost always resulted in on-time projects. But the AOT would need permission from Wilmington and Dover to use the town roads for the detour. “We have no business putting traffic on your roads. But if you give us permission we’d promise your roads would be in as good or better condition after the project is complete. We can also provide police to deter speeding, and we can have uniformed officers (to direct traffic) at peak times.”
The project wouldn’t begin for at least two years, and Williams said the annual construction window for bridges is between June 1 and September 1, when water levels are lower and the ANR will allow work in the stream.
Williams said the accelerated bridge program, which has been used for numerous projects in Vermont since 2007, saves money and reduces impact to nearby residents and businesses.
But Deerfield Valley Transportation Association (MOOver) General Manager Randy Schoonmaker said the impact on the MOOver would be devastating. The Dover/Wilmington route over Route 100 is one of the bus line’s busiest, serving as a hub route for DVTA routes that extend all over southern Vermont. Schoonmaker said it would disrupt service for residents who are employees at local businesses, people who need to shop for necessities, and people who need to visit doctors’ offices and any number of other local businesses.
Because the MOOver’s funding is fixed, and depends on ridership, Schoonmaker said there is no additional funding for extra trips to serve areas not on the detour route, and the resulting loss of ridership would impact future funding. “It’s a deal breaker for us,” he said. “The whole system becomes meaningless because we lose that whole northern route. What do I tell my riders who depend on public transportation?”
Williams said he didn’t have an answer for Schoonmaker’s dilemma, but said there may be grant money available to mitigate impact. “You know the bus system, you’re a creative guy, we’d look at you to work out the solutions.”
Dover Selectboard Chair Randy Terk said the detour may mean traffic would be reduced through most of West Dover’s business district. He also pointed out that the state’s construction window wasn’t suitable for West Dover’s business cycle. “Our quiet season is mud season and after foliage. We have a lot of things happening between Memorial Day and September 1. Things that might be significantly impacted. Things that might not be able to happen with the bridge closure between June 1 and September 1. We would prefer a temporary bridge.”
Williams said that the next step at the AOT would be to discuss the comments from the meeting before deciding how to proceed. “We may hold another public meeting if a 502 process is required,” he said.
Williams promised to keep Dover and other stakeholders included in the process. “Our recommendation in the report is to close the bridge,” he said. “It’s a faster, safer, lower-cost option. The alternative, if the towns won’t allow us to use their roads for a detour, is to go with a temporary bridge. But be careful what you wish for.”