Transportation Conformity Under the Clean Air Act: In Need of Reform?


 

Publication Date: April 2004

Publisher: Library of Congress. Congressional Research Service

Author(s):

Research Area: Environment; Transportation

Type:

Abstract:

Under the Clean Air Act, areas that have not attained one or more of the six National Ambient Air Quality Standards (currently more than 100 areas with a combined population of at least 159 million) must develop State Implementation Plans (SIPs) demonstrating how they will attain the standards and, once they have attained them, how they will maintain air quality. The Act requires that, in these areas, federal agencies not engage in, approve, permit, or provide financial support for activities that do not "conform" to the area's SIP.

Although a wide range of federal funding and programs is subject to conformity, it is transportation planning (and ultimately highway funding) that is most commonly affected. Before a new transportation plan can be approved or a new project can receive federal funding in a nonattainment area, a regional emissions analysis must demonstrate that the projected emissions are consistent with the emissions ceiling established by the SIP. While some express concern at the potential impact of these conformity determinations in delaying or altering new highway projects, others note that the process simply obligates the federal government to support rather than undermine the legally adopted state plans for achieving air quality.

Conformity lapses have occurred in 63 areas in 29 states and Puerto Rico since 1997. Most of these areas have returned to conformity quickly without major effects on their transportation programs: according to the General Accounting Office, only 5 areas had to change transportation plans in order to resolve a conformity lapse. Nevertheless, the impact of conformity requirements is expected to grow in the next few years for several reasons. First, the growth of emissions from SUVs and other light trucks and greater than expected increases in vehicle miles traveled have made it more difficult to demonstrate conformity. Second, recent court decisions have tightened the conformity rules, making it more difficult to grandfather new projects. And third, the implementation of more stringent air quality standards for ozone and particulates in 2004 means that additional areas will be subject to conformity, many for the first time. Thus, numerous metropolitan areas may face a temporary suspension of highway and transit funds unless they impose sharp reductions in vehicle, industrial, or other emissions.

This report, which will be updated as events warrant, provides an explanation of the conformity requirements, discusses the experiences of metropolitan areas that have experienced a conformity lapse during the last 10 years, and reviews some of the recent proposals for reform. Among the issues raised have been the frequency with which conformity should be demonstrated, whether transportation planning and SIP timeframes are mismatched, and to what extent projects should be "grandfathered" if they were once part of a conforming transportation program. The House and Senate surface transportation bills (H.R. 3550 and S. 1072), the Administration's highway and transit funding bill, are among the bills discussed, as is the Administration's Clear Skies bill (H.R. 999 / S. 485), which proposes changes that would affect the number of areas required to demonstrate conformity.