air quality | Transportation Research and Education Center

Research shows electric vehicles can make sense as fleet cars

Mar 09, 2011

Fleet managers can benefit from buying electric vehicles under certain conditions, according to a research paper by Portland State University associate professor Miguel Figliozzi. The paper marks OTREC’s first electric vehicle-related research accepted for publication in a peer-reviewed journal.

In the paper, set for publication in the Transportation Research Record, Figliozzi presents a vehicle replacement model that compares the benefits of conventional and electric vehicles under various scenarios. Incorporating electric vehicles makes the most sense for heavily used fleets when gasoline prices are high, assuming electric vehicle tax credits continue.

Until their purchase price drops, electric vehicles won’t make financial sense for fleet managers without some incentives. “Tax credits are important, especially at the beginning, given the higher price of EVs,” Figliozzi said. “The federal tax credit is roughly 20 percent of the (Nissan) Leaf’s list price and it makes a difference.”

The model presented in the paper shows that fleets will start to include a few electric vehicles with gas at $4.10 per gallon, assuming the existing tax...

Dr. Figliozzi Selected to lead development of truck efficiency report

Jan 04, 2010

Miguel Figliozzi, OTREC researcher, has been selected to chair a study group that will assist DEQ in developing a report, including recommendations for legislation regarding truck efficiency, reduced idling, and emissions. This report will be submitted to interim environment and natural resource committees of the Oregon Legislature by October 2010 for their consideration and any possible action during the 2011 legislative session. The 2009 Oregon Legislature adopted House Bill 2186, which directed DEQ to study potential requirements regarding the maintenance or retrofitting of medium- and heavy-duty trucks in order to reduce aerodynamic drag and otherwise reduce greenhouse gas emissions. DEQ also plans to study potential restrictions on engine use by parked commercial vehicles, including but not limited to medium- and heavy-duty trucks. Study group members will work with DEQ staff to report findings and recommendations for legislation to the interim legislative committees on environment and natural resources by October 1, 2010.

TRB Showcase of Portland State University student research in transportation: Part 2

The video begins at 2:51.

Adam Moore: Bus Stop Air Quality: An Empirical Analysis of Exposure to Particulate Matter at Bus Stop Shelters

Congested traffic corridors in dense urban areas are key contributors to the degradation of urban air quality. While waiting at bus stops, transit patrons may be exposed to greater amounts of vehicle-based pollution, including particulate matter, due to their proximity to the roadway. Current guidelines for the location and design of bus stops do not take into account air quality or exposure considerations. This study compares the exposure of transit riders waiting at three-sided bus stop shelters that either: 1) face the roadway traffic or 2) face away from the roadway traffic. Shelters were instrumented with air quality monitoring equipment, sonic anemometers, and vehicle counters. Data were collected for two days at three shelters during both the morning and afternoon peak periods. Bus shelter orientation is found to significantly affect concentration of four sizes of particulate matter: ultrafine particles, PM1, PM2.5, and PM10. Shelters with an opening oriented towards the roadway were consistently observed to have higher concentrations inside the shelter than outside the shelter. In contrast, shelters oriented away from the roadway were observed to have lower concentrations inside the shelter than outside the shelter. The differences in particulate matter...

TRB Showcase of Portland State University student research in transportation: Part 1

The video begins at 4:13.

Wei Feng: Impacts of Economic, Technological and Operational Factors on the Economic Competitiveness of Electric Commercial Vehicles in Fleet Replacement Decisions

Electric commercial vehicles (ECV) have the potential to substantially reduce greenhouse gas emissions, noise, and pollution in urban areas. In addition, ECVs have lower per-mile operating costs and potentially lower maintenance costs. However, the initial purchase cost of ECVs is significantly higher than the purchase cost of a conventional diesel vehicle. From a purely economic perspective, there is a cost tradeoff between the low operating and maintenance costs of ECVs and their high initial capital costs. In this paper, a fleet replacement optimization framework is employed to analyze the competitiveness of ECVs. Scenarios with different fleet utilization, fuel efficiency and sensitivity analysis of ten additional factors indicate that ECVs are more cost effective when conventional diesel vehicles’ fuel efficiency is low (8.2 miles/gallon) and daily utilization is more than 54 miles. Breakeven values of some key economic and technological factors that separate the competitiveness between ECVs and conventional diesel vehicles are calculated in all scenarios. For example, in low conventional diesel vehicle fuel efficiency and low daily utilization scenario, ECVs are more competitive when their purchase prices...

Coal, Trains and the Clean Air Act: Demand Analysis of the Ohio River Basin

The video begins at 2:51.

Abstract: Coal-fired electricity plants account for over 50 percent of the nation’s electricity. These plants can purchase coal from a large number of different locations and, often, can have a number of different transportation options. Normally, however, from the array of different options, they use only a handful. We frame the model as that of a cost-minimization with a large number of input choices, characterized by standard Kuhn-Tucker conditions. Empirically, we estimate a system of input decisions that contain both zero and non-zero levels, using a Multiple Discrete/Continuous Extreme Value model. The payoffs from each choice are a function of costs, coal attributes, and unobserved modal attributes, as well as the increased regulation under the Clean Air Amendment Act of 1990.

Busy Streets Are Bad For Cyclists' Lungs, Portland Study Says

“Gasless and Cashless take a Toll” – Sustainable and Non-stop mobility through User Fees

The video begins at 2:55.

With the advent of the alternative fuels, it’s very appropriate that gasoline is based on fossil fuels and becoming ancient history. As the gas tax becomes less and less pertinent to adequately funding infrastructure, electronic cashless non-stop tolling options are a more viable solution to financing new projects and providing mobility to existing infrastructure. There are a number of technologies being evaluated for the future; including global position systems (GPS), existing proprietary radio frequency (RF) systems, open standard dedicated open standard dedicated short range communications (DSRC) systems, or the existing cellular networks are also being considered. This presentation will focus on what technologies are available and what emerging technologies are the most likely to emerge as an effective and affordable approach to funding user fees and infrastructure needs. This presentation will also describe how user fees and tolling systems can help the environment, reduce congestion, and provide effective cashless transportation systems based on equitable user fees.

Webinar: States on the Hot Seat: State Efforts to Reduce Greenhouse Gas Emissions from Transportation

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Webinar: States on the Hot Seat

Transportation accounts for approximately 33 percent of greenhouse...

Can Congestion Mitigation Reduce Emissions?

The video begins at 1:49.

Abstract: Policy-makers, researchers, and activists often assume that traffic congestion mitigation results in reduced motor vehicle emissions without proper justification or quantification. This research investigates under which conditions that assumption is valid by comparing trade-offs between increased efficiency and induced travel. Analyses include investigation of varying vehicle fleets - including advanced-drivetrain vehicles. Results demonstrate that higher levels of congestion do not necessarily increase emissions, nor will congestion mitigation inevitably reduce emissions. These results apply for both roadway capacity expansions and traffic flow improvement projects. We compare the emissions effects of various congestion and emissions mitigation strategies, with particular attention to the roll of trucks and the potential of truck-only facilities. Congestion performance measures are also compared for applicability to emissions trends.

Portland State University