Maryland Takes New Approach to Manage Congestion on I-270
Breaking Bottlenecks and Smoothing Traffic: Maryland Finds Innovative Solution to Ease Serious Congestion on I-270
Faced with serious congestion on Interstate 270 near Washington, D.C., the Maryland Department of Transportation State Highway Administration (MDOT) developed an Innovative Congestion Management project to break 14 bottlenecks and create smoother traffic flow. Officials expect the $100 million “Investing in the Power of Go program” will shave 30 minutes off the average commute.
“We are relieving choke points,” says Steve McVeigh, Project Engineer for MDOT.
I-270 carries traffic from Frederick in Frederick County south to North Bethesda in Montgomery and Frederick counties. As many as 261,000 vehicles travel the corridor daily, which is expected to increase to 300,000 vehicles daily by 2040. The road has one high occupancy vehicle (HOV) lane, four express lanes for through traffic and two local lanes for exiting and entering the interstate. Traffic still backs up. The congestion hampers economic development, since travel remains unreliable.
Governor Larry Hogan proclaimed it the “most congested corridor in our state,” when he announced the winning team for the project.
Improvements, within existing right of way, include lengthening merge lanes and an active traffic management system. There will be no tolling.
The department decided to use progressive design-build delivery. It represents the first time a state transportation department has used this procurement method on a linear project.
“The decision to make it a progressive design-build was made at a high level,” says David Phillips, the Alternative Project Delivery Program Manager with MDOT’s Office of Highway Design. “We had different improvements that could have been done on I-270 but wanted to have a holistic approach and see what best would fit.”
With progressive design-build, the department comes up with goals for the project and puts that out to proposers, contractors, and designers who come up with scope and innovations to deliver the project.
“We want to move as many vehicles through the corridor and improve safety and operations,” Phillips says. “The teams can tell us how best to make those improvements.”
The department selected a team of 16 firms. Concrete General, a heavy highway and bridge contractor in Gaithersburg, Maryland, is the prime contractor and RK&K of Baltimore the lead design firm. The team progressed with the design and negotiated with the state on the contract cost. The main project has independent projects that are severable and do not jeopardize other aspects of the project.
Phillips says what makes progressive design-build different than design-build is that there is no scope of work going in, the project is priced at the time of award, there is an ability to do independent projects, and the department can end any independent contract if officials cannot agree with the design-build team on a price.
“We find the best value for the state of Maryland and award a contract for that price,” Phillips explains.
McVeigh indicates daily reports, material tracking, and accounting differ from traditional jobs because of the progressive design-build methodology. McVeigh stays, “Due to each site being treated as its own individual project under the main project number, each had to be tracked separately to ensure that only the approved amount of funds would be used for each.”
Work began in 2017. Five of the projects have been completed.
“We have already seen some travel time savings,” Phillips reports.
Concrete General currently works on three sections. On I-270/I-495 westbound, it is creating a new travel lane on I-495 westbound from the I-270 HOV lane. On I-270 southbound from MD 28 to MD 189, the department is adding a third local lane. And on I-270 southbound from Montrose Road to Democracy Boulevard, crews are adding a new express lane. It will become six lanes when complete.
“The most challenging thing has been the maintenance of traffic, especially at night,” McVeigh says. “When you close three to four lanes of an interstate, often the speed of the car does not change, and we have had numerous accidents.”
The department has allowed 24-hour shoulder closures for the duration of the project. It has added a law enforcement presence to help control traffic flow and keep the speed down in the work zones.
In all areas where projects are currently active, the work taking place includes milling and resurfacing, striping, road widening, wedge and level paving. The road is paved with 12.5-mil asphalt.
Crews also are installing an automated smart traffic flow management system, with cameras and sensors to determine traffic density and adjust entrance at the on ramps at 30 locations. Ramp signals will let drivers know when to proceed. Traffic can enter when the sensors detect a gap in the mainline traffic.
“Ramp metering creates artificial gaps,” Phillips says. “You get into the mainline quicker, and the mainline traffic can continue to flow.”
This will be the first time ramp metering and dynamic speed technology has been used in the state.
Message boards will communicate with drivers in real time. The posted speed limits will increase or decrease based on traffic and established algorithms.
“It is a way to talk to the traveling public and give them an idea of what is ahead,” Phillips says. “The sensors in the roadway tell the speed.”
Motorists may choose to exit the highway if there is an accident or some serious delay ahead.
The ramp metering and traffic management systems will be turned on after all of the construction is complete. The department expects the entire project to be finished by spring 2021.
“I’m proud my team and I are getting to run the first project of this type in Maryland,” says McVeigh, adding that they worked with many departments within MDOT SHA to come up with new ways to track the project. “We all have the same goal – a good project that runs smoothly with few problems.”