Evaluating the impacts of driver performance and driving environment on fuel consumption, emissions and air quality

Ana Marta de Vitorino Faria

Key information

Authors:

Ana Marta de Vitorino Faria (Ana Marta de Vitorino Faria)

Supervisors:

Tiago Alexandre Abranches Teixeira Lopes Farias (Tiago Alexandre Abranches Teixeira Lopes Farias); Patrícia de Carvalho Baptista (Patrícia De Carvalho Baptista)

Published in

December 19, 2018

Abstract

The transportation sector still heavily depends on oil resources, being an important source of environmental degradation in the form of air pollution, global warming and noise. The most traditional approaches to address these issues rely on the development of alternative vehicle technologies and energy pathways, regulatory interventions, and technological improvements. However, focusing on the user/driver, in order to educate him/her towards a more sustainable travelling/driving behavior, might provide additional opportunities for energy savings and avoided emissions. As a result, the main objective of this PhD research program was to evaluate the links between driving environment and driving performance/behavior, by understanding, from large-scale real world driving data, how fuel consumption and emissions are influenced by variables such as the vehicle itself (age, type, etc.), the driver characteristics, road infrastructure, meteorological conditions and traffic volumes. The main findings of this dissertation indicate that weather conditions play a significant role on driving behavior with consequent impacts on air quality. Speed reductions of up to 23% were observed when comparing heavy rain conditions with dry weather, with a similar trend for average acceleration/deceleration (with reductions of up to 10% for heavy rain conditions). Moreover, just the fact of having light rain leads to a 15% reduction on average speed. Regarding wind, average speed decreases by 20% between light wind and strong wind conditions but no substantial variation was found in average acceleration and deceleration. Although drivers adjust their driving behavior according to adverse weather conditions (revealing safety awareness), considering the effect of rain, this change in driving behavior leads to increased air pollutants concentrations. However, regarding the influence of wind, the impacts on driving behavior and, consequently, on air quality are outweighed by the favorable dispersion conditions. When considering the influence of street function (street level), the differences found in driving behavior seem to be more a consequence of the infrastructure characteristics than an adjustment of driving behavior. While speed decreases by 66% from level 1 to level 4 streets, average acceleration and deceleration are higher on more local streets (level 2, 3 and 4). Also, factors related to driver and road context were found to have considerable effects on driving behavior and, consequently, in fuel consumption and emissions of local pollutants. Even if vehicle-related factors are known to be highly relevant in fuel consumption and emissions, findings showed no significant differences in driving behavior due to these factors.