Off-model tools are introduced, the role of off-model tools in supplementing regional network model-based conformity analysis is discussed, and the impact that these tools have had on recent conformity determinations in three nonattainment areas is assessed. The impact of off-model tools is examined through case studies from Chicago, Illinois; Richmond and Hampton Roads, Virginia; and statewide in Pennsylvania. In Chicago, Richmond, and Hampton Roads, the transportation improvement program or long-range plan conformity documentation was reviewed to determine what role off-model tools had in conformity analysis and what impact they had in conformity determinations. In Pennsylvania, projects were reviewed to assess the transportation and air quality impacts of a range of individual projects. Three primary conclusions can be drawn from the analysis: (a) off-model tools have had a significant impact in conformity analyses--often enabling a region to demonstrate conformity, (b) the data requirements are extensive and data collection may prove to be more time consuming than anticipated, and (c) off-model tools generally do not provide a framework for assessing the synergistic or systemic effects of projects. Further developments in off-model tools should focus on integrating off-model analysis with regional travel demand modeling processes and project data bases in an effort to develop a truly comprehensive modeling framework. (Off-model tools are defined as a broad group of sketch-planning tools that use empirical locally gathered data and simple spreadsheets or other data management software to analyze the transportation and air quality impacts of a project.)


  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 19-25
  • Monograph Title: Transportation-related air quality and energy
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00725651
  • Record Type: Publication
  • ISBN: 309062152
  • Files: TRIS, TRB
  • Created Date: Sep 24 1996 12:00AM