OVERVIEW

The Regional Transportation Plan must demonstrate conformity with federal Clean Air Act requirements as set forth in U.S. Environmental Protection Agency regulations.  Without conformity, the Plan cannot be fully adopted and the advancement of transportation projects is severely limited.

In order to demonstrate conformity, an assessment of air quality in the SJTPO region was performed. The purpose of the assessment was to show that the improvements proposed in the Plan would result in the generation of emissions that are below the applicable emissions budgets, thereby demonstrating conformity.

Computer models were used to generate estimates of mobile source emissions resulting from the highway system.  Conformity was determined by testing estimated emission levels against applicable emission budgets for the required test years.  These years included: 2002, the anticipated milestone year under the upcoming Rate of Progress Plan; 2005, the Ozone attainment year; 2007, the CO budget test year; 2015, the interim year; and 2025, the RTP’s horizon year.

As the SJTPO region is designated non-attainment for ozone, emissions of volatile organic compounds and oxides of nitrogen, precursors of ozone, were evaluated.  Portions of the SJTPO region have also been designated as maintenance areas for carbon monoxide.  Therefore, carbon monoxide emissions were evaluated in Salem and Atlantic Counties.