Concerns about the parkway proposed for the outer suburbs of Northern Virginia launched a debate over the direction of change: Is it more important to improve transportation east-west or north-south?

Whether the Virginia Department of Transportation is right or wrong to be pushing for a parkway west of Manassas National Battlefield Park, it’s true that travelers need help all around the compass. An over-reliance on traffic or transit routes in a particular direction will lengthen commutes for today’s travelers while limiting the ability of local leaders to focus development.

VDOT says some of the slowest north-south travel in Northern Virginia is on routes 15, 28, 234, 286 (the Fairfax County Parkway), 294 (the Prince William Parkway), 606 (the Loudoun County Parkway) and 659 (Gum Spring Road). The east-west congestion champs include Interstate 66 and routes 7, 29, 50 and 267 (the Dulles Toll Road).

But two corridors are most prominent in the debate over the parkway plan. There are key differences in Virginia’s approach to how people and goods will move through them.

Interstate 66

This east-west interstate has few rivals in the entire D.C. region for long stretches of slow-moving traffic. In a Monday night presentation in Manassas, Charles Kilpatrick, the VDOT chief deputy commissioner, outlined the state’s improvement plans, which are basically designed to move the most people through the existing travel space.

●VDOT and the Virginia Department of Rail and Public Transportation are studying various ways to improve mobility on the 25 miles between Route 15 in Haymarket and the Capital Beltway. Rather than recommending a single solution, they probably will endorse several fixes that could include adding regular travel lanes; adding managed lanes, possibly high-occupancy toll lanes; targeting the worst choke points for improvements; extending transit in the median, which could be Metrorail, light rail or bus rapid transit; and extending VRE service along the Manassas Line.

●While the grand study continues, VDOT also has a plan to widen I-66 by one regular lane and one HOV lane in each direction for 2.6 miles between Route 15 in Haymarket and Route 29 in Gainesville. The widened segment would have a total of four lanes in each direction.

●Planners are designing I-66 interchange improvements at Route 15 in Haymarket and Route 28 in Centreville, both of which are major north-south commuter routes for the outer suburbs.

●VDOT is about to begin installing an “active traffic management” system of sensors and electronic signs along 34 miles of I-66 between Gainesville and the D.C. line. When the system begins operating by early 2015, it will collect information about the state of the roadway and use it to better manage incidents that are disrupting traffic. Drivers will see new signs telling them to slow down, change lanes or seek alternative routes, depending on the problem ahead.

●Inside the Beltway, VDOT is designing a second “spot improvement” to add an acceleration/deceleration lane to the westbound side of I-66 between Westmoreland Street and Haycock Road. A total of three spot improvements are planned, widening the westbound side for short stretches without broadening the interstate’s right of way.


North-south corridor

Just west of Manassas, the I-66 corridor intersects with state plans for a north-south transportation corridor, and right now, this is the crossroads of discontent.

Everybody can see the problem with I-66: A big highway can’t handle all the traffic that wants to use it. The state’s proposal for a north-south fix is a much tougher sell. Many in the nearby communities say the state’s solutions don’t match the transportation problems they experience. Another important difference: The solutions involve roads that don’t exist yet.

These are the basic elements, at least at present.

●The 45-mile north-south corridor as defined by the state consists of the area near Route 234 from I-95 to I-66, the proposed route of the Bi-County Parkway between I-66 and Route 50, and a path to the Dulles Greenway and Route 7 west of Dulles International Airport and east of Route 15.

●The north-south corridor master-plan study has been underway for about a year. Among its stated goals: Improve north-south access to Dulles Airport, enhance economic activity, address the problems of linking people and businesses in a congested region, and evaluate travel options that include traffic and transit.

●While not the only contentious part of the corridor plan, the proposed Bi-County Parkway — which would run for 10.4 miles between I-66 and Route 50 — is the most hotly debated. It would connect at I-66 with Route 234 (the Prince William Parkway) and continue north as a limited-access highway along the west edge of Manassas National Battlefield Park to an interchange with Route 50 in Loudoun County, west of the airport.

●The Manassas National Battlefield Bypass is tied to the parkway plan. The bypass would follow the route of the parkway north along the west side of the battlefield park, loop around the northern side, then connect with Route 29 on the east side. Inside the park, routes 29 and 234 would be closed to through traffic, fulfilling a dream of the National Park Service.

Advocates say the combination of parkway and bypass will reduce congestion and increase mobility in the Manassas area. But many people who oppose construction of the parkway also oppose closing the routes through the battlefield park. They are seen as important links in the local transportation system and, for some, an alternative to I-66.

●North of Route 50 and west of the airport is the proposed route of the Dulles Air Cargo, Passenger and Metro Access Highway. One way or another, this new, limited-access roadway would link the airport with the Bi-County Parkway. “Metro Access” is a reference to the Silver Line’s second phase (to the airport and into northern Loudoun County).

The access-highway route is of concern to neighborhoods west of the airport, and the highway location study will be the subject of a public hearing from 6:30 to 8:30 p.m. Thursday at Creighton’s Corner Elementary School, 23171 Minerva Drive in Ashburn.