Development of Decision Tool for Strategies to Reduce Greenhouse Gas Emissions

Abstract

The National Household Travel Survey (NHTS) provides important information for the development of local and regional models to support decision making related to climate change and sustainability goals. This paper documents the use of NHTS data in the development of the Greenhouse Gas Statewide Transportation Emissions Planning (GreenSTEP) model, which forecasts estimates of greenhouse gas emissions at county and urban area levels. The model was developed to be sensitive to a broad number of policy variables and other factors that were not addressed in existing models. Because there was a lack of local and current sources of information about individuals, households, and their vehicle ownership patterns and travel behavior, GreenSTEP made use of the information in the national sample of the 2001 NHTS to estimate several model modules. The NHTS data were useful specifically in the development of modules on (a) land use characteristics, (b) vehicle ownership, (c) vehicle use [daily vehicle miles traveled (DVMT)], (d) impacts of vehicle travel costs on DVMT, (e) lightweight vehicles (bicycles, mopeds, electric bicycles, etc.), and (f) vehicle fleets (type and age). The NHTS data were particularly important for modeling the adoption and use of limited-range electric vehicles, as the data enabled estimates of trip length distributions to be made. This paper highlights the utility of the NHTS data for this modeling framework, the modifications and augmentations that were necessary, the limitations that were encountered, and the potential for the wider dissemination and use of the GreenSTEP tool because the initial estimation was made with a national sample.