Grantee Research Project Results
Integration of Air Quality Monitoring and Transportation Planning for Exposure Mitigation in Urban Roadway EnvironmentsEPA Grant Number: FP917473
Title: Integration of Air Quality Monitoring and Transportation Planning for Exposure Mitigation in Urban Roadway Environments
Investigators: Kendrick, Christine M
Institution: Portland State University
EPA Project Officer: Just, Theodore J.
Project Period: September 1, 2012 through August 31, 2015
Project Amount: $126,000
RFA: STAR Graduate Fellowships (2012)
Research Category: Academic Fellowships , Fellowship - Environmental Science
Urban populations encounter short- and long-term exposures of increased vehicular emissions within roadway environments, but air quality effects in transportation planning traditionally are evaluated based on regional, airshed models that do not capture the impacts of these exposures. This research will integrate more refined measurements of traffic-related pollutants with traffic monitoring during the implementation of a large-scale traffic signal intervention on an urban corridor. Roadside monitoring data for air pollutants, traffic parameters and local meteorology will be used to develop models to assess impacts of traffic modifications on long-term localized and short-term corridor exposures at a project-level scale.Approach:
Air quality and traffic monitoring will occur on SE Powell Boulevard, a key regional commuter corridor, connecting highway US 26 to and through Portland, OR. The corridor’s surrounding area is populated densely with residences, schools and businesses and carries a high compositional mix of traffic, including freight trucks, passenger cars and trucks, public transit buses, bicyclists and pedestrians. The corridor is switching from a set-timed traffic signal system to an adaptive traffic control system that will respond to traffic volume, queues at intersections and transit priority signals. This research will integrate continuous measurements, over multiple years, of air pollutants PM10, PM2.5, particle number concentrations (PNC), NO2, CO and CO2; traffic dynamics (speed, volume, classification), and meteorology (wind speed, wind direction, temperature, relative humidity) using permanent roadside stations. Separate field deployments of portable equipment also will be used to measure concentrations along the study corridor, along major roads intersecting the corridor, and dispersion into roadside parks, school lots and neighborhoods.Expected Results:
Data collected will be used to build models to investigate direct temporal relationships between acceleration, deceleration, queue lengths, fleet composition, meteorology and roadside air quality. Vehicle queues in the directions of heaviest traffic will be minimized once the traffic signal system is optimized. It is expected that maximum and average PM10, PNCs and NO2 concentrations will be reduced because of shorter queues at major intersections and less frequent acceleration and deceleration events. PM2.5 concentrations may remain the same as fine PM background levels of urban areas can lead to a more homogeneous pattern for this pollutant. PM2.5 hotspots may arise due to building geometry and meteorology. Monitoring results and emissions modeling will be combined with near-field dispersion modeling to incorporate the surrounding built environment and investigate such spatial patterns. This model development will be used to quantify and visualize traffic emissions spatially within built roadway environments as well as simulate and compare emissions from alternative traffic modifications.
Potential to Further Environmental/Human Health Protection
Transportation is an essential and daily component of lives across the globe. The adverse human health effects from long- and short-term exposures to increased roadway pollution pose a critical demand on transportation policy to reduce impacts of motor vehicle emissions. Integrated air quality and transportation planning on a project-level scale in addition to a regional scale can help target the high impacts of roadway environments and attain urban sustainable development goals like emissions mitigation more efficiently.