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Purpose of this Document

The Clean Air Act section 176(c) requires that federally supported highway and transit project activities be consistent with state air quality goals, found in the state implementation plan (SIP). The process to ensure this consistency is called Transportation Conformity. Conformity to the SIP means that transportation activities will not cause new violations of the national ambient air quality standards (NAAQS), worsen existing violations of the standard, or delay timely attainment of the relevant standard.

Transportation conformity is required for federally supported transportation projects that are located in areas that have been designated by the U.S. Environmental Protection Agency (EPA) as not meeting a NAAQS. These areas are called nonattainment areas if they currently do not meet air quality standards or maintenance areas if they have previously violated air quality standards, but currently meet them and have an approved Clean Air Act section 175A maintenance plan.

On January 5, 2005, the EPA designated areas within the country as nonattainment for fine particulate matter, called PM2.5. This designation became effective on April 5, 2005, 90 days after EPA's published action in the Federal Register. Transportation projects that are proposed after April 5, 2006 (i.e., after the one-year grace period provided by the Clean Air Act) must demonstrate compliance with the conformity rule for the PM2.5. In addition, designated PM2.5 nonattainment areas must have in place both a long range transportation plan and transportation improvement program (TIP) that complies with the conformity rule, and federally supported projects must also demonstrate conformity. For PM2.5, project-level conformity may also require an assessment of localized emission impacts, known as a hot-spot analysis, for certain projects.

The Woodrow Wilson Bridge project is located in Fairfax County, Virginia and Prince George's County, Maryland. Both counties are within the designated Washington, D.C.-Maryland-Virginia PM2.5 nonattainment area. As such, the project is required to meet Transportation Conformity requirements found in 40 CFR Part 93. Although much of the overall Woodrow Wilson Bridge project is already under construction or complete, several phases remain that still require FHWA authorization. As discussed on FHWA's frequently asked questions website for "PM2.5 Project-Level Conformity and Hot-Spot Analyses1," if a project still requires a FHWA approval or authorization, a project-level conformity determination is required prior to the first such action on or after April 5, 2006, even if the project has already completed the NEPA process, or for multi-phase projects, even if other phases of the project have already been constructed. The purpose of this document is to provide analysis and support for such project-level PM2.5 conformity determination for the Woodrow Wilson Bridge project.

Therefore, in accordance with FHWA's frequently asked questions2, the hot-spot analysis will focus on those phases of the project area that are not already under construction or are not completed and require a new FHWA authorization.

Project Description

The Woodrow Wilson Bridge Project is a complex bridge and interchange improvement project jointly sponsored by the Maryland Department of Transportation's State Highway Administration, Virginia Department of Transportation, Federal Highway Administration and the District of Columbia Department of Transportation. This multi-jurisdictional project traverses a diverse human environment, passing from Fairfax County to Alexandria, Virginia to the District of Columbia, to Prince George's County, Maryland (Figure 1).

The 7.5-mile Wilson Bridge Project is replacing the existing six-lane bridge with two six-lane, side-by-side drawbridges and rebuilding the surrounding four interchanges (Interstate 295 and Maryland 210 in Maryland and U.S. Route 1 and Telegraph Road in Virginia). The new bridge is designed to be transit ready for HOV, express bus or transit and to serve motorists for approximately 75 years. To better serve motorists, pleasure boaters and commercial vessels, it is 28 feet higher at its apex to provide extra clearance so that bridge openings will be reduced by 75 percent.

In its sixth year of construction, the Wilson Bridge Project is one of the largest transportation projects under construction in the United States and is 60 percent complete and on schedule. The project remains on-budget, with the $2.4 billion cost estimate being virtually unchanged from the original 2001 estimate (despite reflecting additional elements that will benefit the traveling public).

The project met a major milestone by opening the first new bridge in summer 2006 to carry all six lanes of Capital Beltway traffic (three in each direction). The second new bridge is scheduled to open in the summer of 2008. Once completed, the entire new facility will offer twelve lanes: eight lanes to match the eight-lane Capital Beltway, two lanes to facilitate merging/exiting and two lanes for future rail transit, bus service or high-occupancy vehicles. The year 2008 also will see the substantial completion of the project as defined in the record of decisions (completion of Interstate 295, Maryland 210 and majority of the US Route 1 Interchanges), resulting in approximately 90% of the project complete. Finally, despite the addition last year of major improvements to the Telegraph Road Interchange, this last element of the project remains slated for 2011 completion.

For more project information, please visit

Figure 1 ­ Project Layout
General roadmap showing location of the entire Woodrow Wilson Bridge project.

The phases of work that remain to be authorized in Prince George's County, Maryland (Figure 2) are:

Detailed roadmap showing the location of phases MA-5, MB-5, and MM-6.

The phases of work that remain to be authorized in Fairfax County, Virginia (Figure 3) are:

Detailed roadmap showing the location of phases VA-8, VB-2/3/6, VM-5, and VM-6.

2 See Question 5.
Updated: 1/10/2017
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