Fuel Use and Emissions Comparisons for Alternative Routes, Time of Day, Road Grade, and Vehicles Based on In-Use Measurements

Abstract

The objective here is to quantify the variability in emissions of selected light duty gasoline vehicles by routes, time of day, road grade, and vehicle with a focus on the impact of routes and road grade. Field experiments using a portable emission measurement system were conducted under real-world driving cycles. The study area included two origin/destination pairs, each with three alternative routes. Total emissions varied from trip to trip and from route to route due to variations in average speed and travel time. On an average trip basis, the total NO emissions differed by 24% when comparing alternative routes and by 19% when comparing congested travel time with less congested traffic time. Positive road grades were associated with an approximately 20% increase in localized emissions rates, while negative road grades were associated with a similar relative decrease. The average vehicle-specific power based NO modal emission rates differed by more than 2 orders of magnitude when comparing different vehicles. The results demonstrate that alternative routing can significantly impact trip emissions. Furthermore, road grade should be taken into account for localized emissions estimation. Vehicle-specific models are needed to capture episodic effects of emissions for near-road short-term human exposure assessment.

Chemical composition of PM 2.5 from two tunnels with different vehicular fleet characteristics

“…Several different approaches have been employed to investigate vehicle emissions, including the engine dynamometer test (Na et al, 2015;Pietikainen et al, 2015), on-road test (Durbin et al, 2008;Frey et al, 2008) and tunnel test (Ho et al, 2009;Pio et al, 2013). Tunnels are usually constructed to ease traffic congestion, and because of the confined space, there is an increase in the concentrations of the emissions and prolonged exposure to the pollutants emitted by the vehicles (El-Fadel and Hashisho, 2001).…”

Advanced Impact Integration Platform for Cooperative Road Use

“…Pereira et al, 2014 developed an eco-friendly app an based on GPS data and demonstrated that the routes defined by SmartDecision app can provide a 15%-32% reduction in health and social costs when compared with the recommended Google route. Empirical studies based on real world driving cycles data tend to be focused on individual impacts of a single vehicle Frey et al, 2008;Minett et al, 2011) traveling on several routes, whereas analytical studies based on traffic simulation models are generally used for assessing the impacts of eco-routing strategies within the whole network (Ahn and Rakha, 2013;Ferguson et al, 2012;Guo et al, 2013;Levin et al, 2014). These methods conglomerate traffic and mobile-source energy and emission models with route minimization algorithms which are employed for routing proposes.…”

“…According to different authors, this type of models tend to be more realistic than average speed models Folberth et al, 2006) and especially in the context of comparative analysis of different routes (Ahn and Rakha, 2008;Bandeira et al, 2014;Frey et al, 2008). The methodology used to estimate emissions was based in the Vehicle Specific Power (VSP) which is built on regression models and allows characterizing the vehicle activity data on a second-by-second basis.…”

Effects of Travel Routes on Vehicular Emissions in Urban Driving

“…The study also showed an increasing number of motor vehicles and motorcycles in these locations which were the major contribution of air pollution. Frey HC [2] conclude that positive road grades were associated with an approximately 20% increase in localized emissions rates, while negative road grades were associated with a similar relative decrease. This study has help in further understanding the relationship between emissions and fuel consumption in roads with vary grade, altitude and average speed of travel.…”