The Federal Highway Administration (FHWA) Office of Planning, Environment and Realty's (HEP) Surface Transportation Environment and Planning Cooperative Research Program (STEP) ended on September 30, 2012. For current HEP research information, please see HEP's research web site.
This research has been funded by the Federal Highway Administration's Office of Planning, Environment and Realty's Surface Transportation Environment and Planning Cooperative Research Program (STEP).