This study employs a multilevel model to compare the influence of land use on transportation emissions in urban and suburban areas when considering trip speed and vehicle characteristics. In the existing literature, transportation emissions are calculated with aggregate travel activity and emissions factors, however, emissions factors are sensitive to trip speed and vehicle characteristics, implying that considering those factors can change transportation emissions as well as the estimated effects of the built environment. Our results show that indeed this true.
Hong, Jinhyun, and Anne Goodchild. "Land use policies and transport emissions: Modeling the impact of trip speed, vehicle characteristics and residential location." Transportation Research Part D: Transport and Environment 26 (2014): 47-51.