Institute of Transportation, MOTC

Title	Relation analysis between energy consumption, emissions and transportation planning (1/2)
Dept	Transportation Planning and Land Transport Division
Year	2008
Month
Price
Summary	From the perspective of transportation planning, this project examines the correlations of highway traveling behavior with vehicle energy consumption and emissions. The correlations we measured are based on realistic data, which is collected in a second-by-second method and from a running vehicle equipped with the On-Board Emission Measurement. Our core concept is to explore the feasibility of developing an “integrated evaluation framework” (IEF) which is capable of incorporating vehicle dynamic performance of energy consumption and emissions into the aggregate sequential travel demand model. Unlike the traditional mainstream, which estimates vehicle energy consumption and emissions on the trip-base, with parameters of distance measured by l/km or g/km, and from laboratory testing, we approach it on the link-base with parameters of travel-time vs. running-speed at link-category, namely g/sec, from a series of on-road surveys. The IEF we are working on is expected to enable us to establish the sensitive correlations of vehicle energy consumption and emissions with travel time, running speed variations and traffic diversions among network links. Eventually, with the correlations of traffic dynamics with energy consumption and emissions, the IEF shall lead to the establishment of an operational tool to enhance the sustainability of transportation planning and project evaluation practically.   The multi-year project, with an aim of model construction, may result in the incorporation of vehicle energy consumption and emissions into the aggregate sequential travel demand model. The findings of the first-year pioneer study tend to suggest that our innovative concept of the IEF is feasible and workable. The main achievements in the first year are listed as follows: 1. Exploration and Concept Development of The IEF (1) A comprehensive review of the relevant literature lends support to our research design. (2) We identify highway-traveling behaviors that can significantly affect vehicle dynamic performance of energy consumption and emissions. 2. The Survey and Analysis of the Correlations of Vehicle Dynamic Performance of Energy Consumption and Emissions (1)Experiments are designed and executed to build up the dataset that contains over 200,000 records on one vehicle of five kinds of link-category. (2)A set of functions are constructed to estimate vehicle energy consumption and emission rate, of CO2, CO, THC, and NOx respectively, vs. running-speed at each link category, in terms of g/sec. (3)Analyses are conducted to investigate the dynamic factors that may significantly affect vehicle performance of energy consumption and emissions. Comparisons made include driving cycle (FTP/EU/Taipei Metropolitan/Taichung Metropolitan/Kaohsiung Metropolitan), usage of headlight and air-conditioner, measurement condition (on-road vs. lab), and grade.   Based on the above achievements, we shall proceed further with on-road surveys and corresponding laboratory experiments, with more vehicles, in order to calibrate the correlations of highway traveling behavior with energy consumption and emissions, eventually with robustness. In addition, a case study will be conducted to demonstrate the potential applications of the correlations measured, with an aim to integrate with the aggregate sequential travel demand model.
Post date	2008/06/23
Hashtags