This study seeks to examine the potential impacts of Advanced Public Transportation Systems (APTS) technologies in terms of vehicle emissions, air quality, and fuel consumption. The potential impact of APTS technologies on pollutant emissions and fuel consumption are examined. The results invite some skepticism about the potential benefits of APTS technologies in these areas. Areas of concern are discussed, and recommendations are made regarding how program emphasis be given to those APTs technologies and services that can attract travelers from auto to transit without increasing bus miles.