BANGOR, Maine — State transportation officials are considering an unconventional approach to the safety and congestion problems at Interstate 95’s Hogan Road interchange which, with an average of about 35,000 vehicles using it each day, is considered the busiest in the state, according to the Maine Department of Transportation.
A proposed redesign of Exit 187, which would result in an unusual traffic flow configuration on the bridge, is the subject of an informational meeting set for 6-8 p.m. Thursday at Mathieu Auditorium in Eastern Maine Community College’s Schoodic Hall.
The exit was built in 1960, according to the Maine Department of Transportation. The Hogan Road bridge underwent a major widening in 1983. The nearby Stillwater Avenue exit was added in 2001, and the Bangor Mall area has seen increased development and developer projects in recent years.
As it stands, the interchange has safety problems and often is congested, according to the Department of Transportation. There also are no sidewalks or adequate shoulders on the bridge for pedestrians and bicyclists.
The interchange has three high-crash locations, with 94 collisions in the latest three-year period, 72 of which occurred at the two traffic signals on the bridge, according to a powerpoint presentation the Department of Transportation prepared in anticipation of Thursday’s meeting. The presentation was posted on the agency’s website.
Thirty-six percent of the collisions resulted in injury, state officials said.
To that end, the state is proposing a “diverging diamond” interchange, which if built would be the first in Maine, Edward Hanscom, the state transportation department’s head of transportation analysis, said Wednesday.
“We first started looking at this in 2014,” Hanscom said. “First of all, we wanted to learn a lot more about diverging diamond interchanges because it’s a new concept for Maine.
“We spent time researching that, and we knew that Exit 187 had high-crash locations and congestion issues at certain times, so we wanted to see if that was a viable alternative at the Hogan Road exit,” he said.
“And so we did analysis, capacity and safety, and determined that it was probably the best choice we had available to us,” he said.
“The thing it does for safety is reduce conflicts between vehicles,” Hanscom said. “It reduces the number of opportunities vehicles have to cross each others’ paths, and when you can reduce those conflicts, you reduce crashes because that’s where crashes happen, at conflict points.”
In addition, lowering speeds would minimize the severity of those crashes that do occur.
Nationally, 57 such interchanges have been built since 2009, and 26 states either have built them or have them under construction, according to the Department of Transportation.
State officials say that the diverging diamond interchange design has been shown elsewhere to reduce crashes by about half, while increasing mobility and reducing congestion to prevent backups onto I-95. It also would provide for a dedicated bicycle/pedestrian-protected path within the width of the existing bridge.
Hanscom said the current plan is to continue using the existing bridge, which has an estimated service life of about 10 more years.
The state has $250,000 set aside for design work, which will result in a firm project cost, Hanscom said. He said, however, that the total cost likely will be somewhere between $3 million and $5 million.
The project would occur in 2018 or 2019 at the earliest, Hanscom said.