WASHINGTON – Traffic flow on key stretches of Interstate 66 is at failing levels during rush hour.
A new study finds the amount of time that I-66 is jammed could double to ten hours a day in each direction within 30 years.
“The existing roadways are over capacity now,” says Angel Deem, VDOT environmental project manager. “Through our analysis when we just ran the traffic model to say ‘okay, if you were to add traditional highway lanes, how many would be needed?’ and it comes out to nine additional lanes in each direction, which of course is not sensible.”
The Tier 1 Draft Environmental Impact Statement on multimodal options in the I-66 corridor from the Beltway to Haymarket finds that a “no-build” situation, which would leave things as-is, is simply not a viable option, either as more people move to the outer suburbs and commute or as people travel to places like Tysons Corner and the District.
Among the problems identified beyond a lack of multimodal options is how hard it is to predict how long a trip will take.
“The lack of predictability for travel in the corridor adversely affects the quality of life for travelers in the corridor, and also makes it difficult for travelers to make decisions about when to travel and which mode to take,” the draft says. “In addition, it adversely affects both travel times and service predictability for the bus services that make use of the I-66 roadway.”
The study looks at options that include adding new regular lanes to I-66, adding HOT lanes, extending the Orange Line to Centreville or Haymarket, extending VRE’s Manassas Line to Haymarket or building a dedicated bus rapid transit or light rail system.
After looking at 47 different combinations, the study finds that none of the options would be enough on its own.
“The combinations may ultimately be projects that spin off from this tiered document, but the goal of this analysis isn’t to say, ‘We pick improvement concept 23,'” Deem says.
The study does find that high occupancy toll lanes like the Beltway Express Lanes, along with some kind of fixed transit, provide some of the best space- and capacity-efficient options.
Since all of the significant improvements that were analyzed would cost billions of dollars, the true “best mix” of projects depends on what exactly planners are looking for.
The study finds that adding two HOT lanes in each direction, plus a Metro or VRE extension or other new transit option, would be among the best ways to accommodate total expected travel demand. Another good option would be to add the same HOT lanes with four additional general purpose lanes.
It also suggests that cheaper, short-term solutions could include improvements at nine key chokepoints along I-66, as well as better communication with commuters about what the best options are on a given day.
The draft finds that commuters today save about 12 minutes over the main lanes by using the eastbound HOV lane in the morning and about seven minutes by using the westbound lane in the evening.