scholarly journals Evaluating the Environmental Impact of Bus Signal Priority at Intersections under Hybrid Energy Consumption Conditions

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4555 ◽  
Author(s):  
Ning Huan ◽  
Enjian Yao ◽  
Yulin Fan ◽  
Zhaohui Wang

The acceleration of the motorization process creates severe environmental problems by affecting the energy consumption of urban traffic. As a major source of traffic pollution, vehicle exhaust deserves more attention when making traffic policy. Actually, the acceleration, deceleration, and idling conditions of vehicles cause more pollution than usual, which mainly happens at intersections of the road network. Besides, in the context of giving priority on public transport development, bus signal priority (BSP) at intersections becomes a quite prevalent measure to reduce average capita delay for travelers, while long-term practice also indicates that the unreasonable setting of bus lane further worsens the running conditions for other vehicles by occupying excessive traffic capacity, which highlights the indirect environmental effects of BSP. This paper provides a simulation-based method for evaluating the adaptability of BSP to find an optimum balance between efficient and environmental care. Specifically, the traffic volume, bus mixed rate of the intersection and energy types of vehicles consist of hybrid energy consumption conditions collectively. A VSP (vehicle specific power)-based exhaust emission models for both buses and other vehicles are employed to estimate the environmental cost of the entire intersection. Moreover, the overall efficiency of gasoline and electric vehicles is further evaluated to offer more implications for traffic control practice.

Author(s):  
Frank Atzler ◽  
Alfred Wiedensohler ◽  
Tilo Roß ◽  
Kay Weinhold ◽  
Maximilian Dobberkau

AbstractUrban traffic is a significant contributor of particulate matter to the environment (Kessinger et al. in https://www.umweltbundesamt.de/sites/default/files/medien/5750/publikationen/hgp_luftqualitaet_2020_bf.pdf, 2021). Hence, there is a high interest in the measured data of roadside immission measurement station. In the federal state Saxony (Germany), the State Office for Environment, Agriculture and Geology (LfULG) is responsible for supervision of the air pollution. In a joint project, the LfULG, the Leibniz Institute for Tropospheric Research (TROPOS) and the Chair of Combustion Engines and Powertrain Systems of the Technical University of Dresden (Lehrstuhl für Verbrennungsmotoren und Antriebssysteme, LVAS) measured the particulate immission* from a selection of passenger cars in an “environment simulation” Weinhold et al. (https://publikationen.sachsen.de/bdb/artikel/36768q, 2020). Especially direct injection spark ignition engines, DISI, without particle filter have a high particulate matter emission, depending on the operating condition. However, an increase of the particulate matter immission due to the rising market penetration of DISI engines was not measurable at the immission measurement stations of LfULG. To investigate the effect of vehicle exhaust emission and immission, an experiment was developed to measure particulate matter immission similar to road conditions on a chassis dynamometer. Five used cars with different engines, exhaust after treatment systems and mileage were evaluated regarding their emissions and particulate immissions. Unexpectedly, a high amount of ultrafine particulate matter smaller 100 nm was found during the emission measurements, although the exhaust emissions were completely extracted to the CVS measurement system. It was concluded that these particles were assignable to break and tire wear. This paper summarizes the most important findings, the complete report is available in Weinhold et al. (https://publikationen.sachsen.de/bdb/artikel/36768q, 2020).


2021 ◽  
Author(s):  
Alberto Pozanco ◽  
Susana Fernández ◽  
Daniel Borrajo

Sign in / Sign up

Export Citation Format

Share Document