Capital Beltway Study

Other Studies | West Side Mobility Study

The West Side Mobility Study was led by the Maryland State Highway Administration (SHA) West Side Mobilty Study and supported by the Virginia Department of Transportation (VDOT). The 14-mile long project extended north from SR 193 in Virginia, along the west side of the Capital Beltway, along the I-270 West Spur, along I-270, to the I-370 Interchange.

The purpose of the study was to evaluate a managed lane system connecting Virginia's HOT Study, Maryland's Capital Beltway Study, Maryland's I-270 Multi-Modal Study, and Maryland’s Intercounty Connector.

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Project Scope
Roadway Sections
Short-Term Improvements
Mid-Term Improvements
Long-Term Improvements
Final Report

Project Scope

The study was performed from the middle of 2006 until Fall 2009 and it included the following tasks:

Evaluated how many trips would be willing to utilize a managed lane along this section of the highway.
Evaluated how existing and future traffic will operate with a managed lane.
Evaluated how many lanes may be needed for a managed lane system to operate effectively.
Developed engineering alternatives to fit the managed lanes within the existing highway system.
Evaluated potential impacts associated with construction of new managed lanes, including property impacts and environmental impacts.
Developed cost estimates for the engineering alternatives.
Prepared a Technical Report summarizing the study efforts and conclusions.

Roadway Sections

The project was separated into five sections as described below:

Virginia portion of the Capital Beltway from the northern limit of VDOT’s HOT Lane Study to the American Legion Bridge
American Legion Bridge
Maryland portion of the Capital Beltway from the American Legion Bridge to the I-270 West Spur
I-270 West Spur
I-270 from the West Spur to the I-370 Interchange

Short-Term Improvements

Improvements were investigated that could be implemented relatively quickly, within one to two years. These improvements were focused on localized congestion points and identified modifications that could improve system-wide traffic operations but would require limited or no widening. These improvements included extending acceleration or deceleration lanes at interchanges; operating the HOV lanes on the I-270 spurs as general purpose lanes during peak periods; or changes to lane configurations to alleviate local congestion.

Mid-Term Improvements

A series of mid-term improvements were considered that would provide increased capacity and a managed lanes network throughout the study corridor, but would require little or no widening. The mid-term improvements were more extensive than the short-term improvements and would therefore take longer to implement, but would be less costly and impactive than the long-term alternatives.

Mid-term improvements included:

Restriping – the existing highway, with the exception of the I-270 East Spur, would be restriped to provide one additional lane in each direction. The additional lane would be created by narrowing the width of the existing lanes and shoulders.
Peak Period Shoulder Use – along the Capital Beltway, I-270 West Spur, and I-270 mainline, the existing left or right shoulder would be used as a travel lane during the peak periods only. This lane would provide additional capacity when it is required, but maintain the left shoulder for breakdowns, enforcement, and incident management during non-peak periods.
Reversible Lane – during the peak period, one lane in the non-peak direction would be operated as a contra-flow lane for peak direction traffic. The contra-flow lane would be separated from the non-peak direction traffic by a movable barrier and from the peak direction by the median. The movable barrier would by placed along the lane line between the left and second to left lanes when deployed and against the median barrier when not deployed.
Convert HOV Lanes to HOT Lanes or General Purpose Lanes – convert the existing HOV lanes on the I-270 Spurs and I-270 mainline to HOT or general purpose lanes. All existing lane and shoulder widths would be maintained. There would be no improvements to the Capital Beltway.

Long-Term Improvements

The State Highway Administration identified five alternatives as part of this study. Three of the alternatives cover a full range of options and they are identified as low, medium, and high. The name of the alternatives relates to the cost, impacts, and the timeframe to get the improvements opened (i.e. the low alternative would have lower costs, lower impacts, and be able to open in the least amount of time). Additionally, there were two other alternatives that were considered as part of the study. The type of managed lanes that were under consideration for these alternatives include high occupancy toll lanes (HOT) and express toll lanes (ETL).

Low

Alternative 1: Operate a one-lane managed lane system in Maryland and a two-lane managed lane system in Virginia.