Vehicle Emissions and Level of Service Standards: Exploratory Analysis of the Effects of Traffic Flow on Vehicle Greenhouse Gas Emissions
Many local jurisdictions seek to preserve adequate infrastructure by enacting level of service (LOS) policies for proposed new development. Understanding the relationship between roadway LOS policies and greenhouse gas emissions is an important step towards reducing the emissions related to global climate change. By influencing the evolution of urban infrastructure, these LOS standards can have a significant impact on the type and character of vehicle trips made and the subsequent emissions released. Currently, most jurisdictions establish LOS threshold policies based solely on operational standards and rarely consider the impacts of greenhouse gas emissions.
Using a travel demand forecasting model for Grover Beach, CA, buildout conditions were simulated to make the network have operational deficiencies in critical areas, ultimately operating at a LOS F. Changes to roadway lane configurations were then made to achieve LOS thresholds of LOS E through LOS A. The resulting speed and flow data were analyzed in emission models to determine the relationship between the target LOS thresholds and emissions produced. The network was modeled for both roadway link LOS and intersection LOS conditions.
For roadway links, overall the lowest amounts of emissions were released at the LOS B threshold and the greatest incremental decrease in emissions occurred between LOS D and C. At intersections, the lowest emissions point was LOS A and the largest incremental decrease occurred between LOS D and C. When considering the feasibility of implementation of LOS thresholds, LOS C was determined to be the most effective operating point for emissions.
Rafael Cobina, Tony Henderson, Sudeshna Mitra, Cornelius Nuworsoo, and Edward Sullivan. "Vehicle Emissions and Level of Service Standards: Exploratory Analysis of the Effects of Traffic Flow on Vehicle Greenhouse Gas Emissions" Proceedings of the 2009 Transportation Research Board 88th Annual Meeting: Washington, D.C... Jan. 2009.
Available at: http://works.bepress.com/cnuworso/13