UVM Student Research Conference 2015

Transportation Research Posters and Presentations

UVM Student Research Conference 2015

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SESSION II:  Morning Presentations: 10:00- 10:45a Title/Details Video|PDF
Jim Dunshee

Civil Engineerin
gTRC Graduate Scholar

Frank Livak Ballroom 417
Particulate Emissions from Biodiesel Blends: Measurement and Trends:

Particulate matter (PM) from diesel engine exhaust is an environmental and public health hazard. In response to increasingly stringent government regulations, diesel PM emission rates have been substantially reduced by means such as emissions control technologies and ultra-low-sulfur diesel (ULSD) fuel. Biodiesel, typically used at ≤20% (v/v) as a blended fuel with petroleum-based diesel, may also reduce PM emissions. The majority of studies, which support a general trend of lower PM emission rates as biodiesel percentage increases, are based on older, heavy-duty diesel engines. Few studies have investigated PM emissions from modern, light-duty diesel engines fueled by biodiesel blends. PM emissions are currently regulated by the gravimetric method: the mass of particles collected on a filter. By this method, low PM emission rates (which result in low corresponding masses) have greater measurement error. A novel, and more sensitive, method is to measure the size distribution of particles (i.e., number by size bin), assume spherical volumes, and apply size dependent densities in order to calculate mass. Measurements of PM by this integrated particle size distribution (IPSD) method have demonstrated good agreement with gravimetric measurements, for both gasoline and diesel vehicles. No prior studies have evaluated the IPSD method for biodiesel emissions, which may require adjustments to the method in order to compensate for differences in particle characteristics (e.g., morphology, density) compared to diesel emissions. For this study, emissions data were collected from a light-duty diesel engine operating on two sets of biodiesel (based on either waste vegetable oil or soybean oil) consisting of five blends each (0, 10, 20, 50, and 100% biodiesel). The current research objectives are to use these data in order to: 1) quantify trends in PM emissions by biodiesel percentage, 2) evaluate the IPSD method for biodiesel emissions, and 3) investigate appropriate adjustments to the IPSD method.

Morning POSTERS: 10am-11:30am Title/Details Video|PDF
Keith Zuckerman

Electrical Engineering


Sensitivity Analysis of Incentive-based Coordinated Charging Control of Plug-in Electric Vehicles:

The penetration of Plug-in Electric Vehicles into the vehicle market has the potential to cause overloading of distribution -level substation transformers, which serve around 100-500 homes. Without coordinated charging, the overload could lead to overheating, significantly reduce life-time, and increase failure-rate of the transformers, resulting in local blackouts. In this thesis, we will be exploring the implementation of a decentralized charging control algorithm, which is well -known to require significant computational overhead. Through simulations and sensitivity testing, we will optimize parameter selection to reduce the computational overhead required for the control algorithm to converge to the optimal price-signal during each time step of implementation.

Julia Ursaki

Civil Engineering
Analyzing the Equity of Bikeshare Access in Three Large American Cities:

Bikesharing programs have arisen as a unique solution to many of the urban transportation system sustainability challenges. However, the social equity aspect of bikeshare sustainability has not been adequately considered, though the equity of a public system is critical in determining its overall success. By using a spatial analysis that compares social and economic characteristics of the areas inside and outside of bikeshare service areas in Boston, Chicago, and New York City, this study suggests that there is inequitable access to bikeshare among city residents. Spatial databases describing the locations of bikeshare docking stations was provided by Movtivate. The scope of the bikeshare systems ranges from 1,300 bicycles in Boston, to 3,000 in Chicago, and 6,000 in New York City. The locations of bikeshare stations were used to define the bikeshare service areas in the Geographic Information System (GIS) ArcGIS. Social and economic data describing race, age, income, education level, and population were gathered from the US Census. These categories were separated into ten variables measuring socioeconomic and demographic attributes. Significant differences in race and income variables inside and outside of the bikeshare service areas were found in all cities. Moreover, in Chicago and New York City, there were also differences in age and education level variables. In all cases, more groups traditionally considered disadvantaged were outside the bikeshare service areas. These results suggest that to combat inequity of bikeshare access, policies such as public subsidies for stations in lower income neighborhoods may be necessary. This study is being continued by this team at the UVM Transportation Research Center by adding Washington DC, Seattle, and Denver to the analysis for a more robust picture of bikeshare access and equity in American cities.

Ben Rukavina

Civil Engineering

Poster 44A

Comparing Reactive Oxidative Species (ROS) Formation on Particulate Matter in Diesel and Biodiesel Exhaust:

As biodiesel fuel use increases due to EPA mandates, it is important to study the relative safety of biodiesel emissions compared to diesel. Particulate matter (PM) is a major component of air pollution and tailpipe emissions and has been linked to many adverse health affects. Though the way that PM impacts health is unknown, there is growing consensus that the formation of reactive oxidative species (ROS) on PM and the subsequent oxidative stress is a possible causative agent for health problems including asthma and decreased lung function. A newly accepted abiotic method to quantify ROS formation uses the rate of consumption of dithiothreitol (DTT) to measure the oxidative potential of PM. In this study, DTT assays were performed using impinge samples of exhaust PM suspended in ethanol. The samples were obtained from burning fuels with different percentages of biodiesel in a light duty-duty diesel engine under controlled laboratory conditions. By comparing the consumption rates of DTT with the biodiesel percentage, one can begin understand which blends may be less harmful in terms of ROS generation. The DTT consumption rate for pure diesel PM, with standard deviation, 32.6nM/min/μg ± 8.6, was more than double that for pure biodiesel, 14.0nM/min/μg ± 2.4, indicating a quantifiable difference between blends. More assays are being performed to define the trend for intermediate biodiesel blends and replicates to increase the precision of the data and examine the reproducibility of the apparent trend.

Matthew Brand

Civil Engineering


Use of Sacrificial Embankments to Prevent Bridge Collapse Due to Scour Under Extreme Events:

The leading cause of highway bridge failure in the United States is bridge scour. High flow events in streams lead to foundational bridge scour by enhancing erosion and scour processes. These bridges are at a critical risk of collapsing during extreme flooding events, and are a major risk to human life and economic sustainability. Currently, agencies and designers have limited resources to predict the increasing severity of flooding that has occurred over the last five decades. Retrofitting the thousands of undersized and scour critical bridges throughout the country to the current standards is prohibitively expensive, and current countermeasures inadequately address the core problems related to scour.Recent research efforts on scour are geared towards modeling and pattern analysis for designing standards for newly built or planned bridges. Very limited research is focused on the design or retrofit standards for the tens of thousands of bridges already built, yet still vulnerable to scour. This research focused on the design and implementation of a simple and effective retrofit for bridges already built using an embankment system that acts as a “fuse” during high flow events. This embankment design increases the streams cross sectional area during high flow events, thereby decreasing the energy and scour potential. This research can provide a more inexpensive, safer, and quicker retrofit for vulnerable bridges compared to current methods.

Posters Noon- 1:30 Title/Details Video|PDF
Anna Schulz

Public Administration

TRC Graduate Scholar


Adapting Bridge Infrastructure to Climate Change in Vermont and Maine:

Climate change is underway and regions across the United States are beginning to see the effects.  The Northeast is especially threatened by sea level rise, heavier precipitation, and more intensestorms. Although federal and state transportation agencies are undertaking a variety of mitigation activities, adaptation and resilience remain under-prioritized. The research presented here surveys existing literature on adaptation practices and presents comparative case studies regarding adaptation in two northern New England states: Vermont and Maine.It investigates and compares prioritization procedures, funding trends, and adaptation-related practices employed by transportation agencies.  This research relies on State Department of Transportation project  prioritization criteria, interviews, a survey of existing literature, and a new bridge funding database, which was compiled using Statewide Transportation Improvement Programs and Capital Programs. Bridges and culverts, which are especially vulnerable to climate-related impacts, are emphasized as critical components of adaptation activities and planning. Certain practices, such as building structures with higher capacity for hydraulic flow, have been undertaken as part of mandates by natural resource councils but also serve to improve transportation resilience. Critical gaps in resources and knowledge serve as barriers to improved adaptation planning, but restructuring the project prioritization procedures used by states and metropolitan planning organizations to explicitly include adaptation may provide opportunities to increase resilience.

Sean Neely

Civil Engineering

TRC Graduate Scholar


Impact of Information Access on Attitudes about Intercity Travel by Automobile, Bus, and Passenger Rail:

Much research exists on intercity travel behavior between large metropolitan areas. There is an opportunity for more research on travel from less populated areas to large metropolitan areas. When planning a trip from Northern New England to major cities in the Northeast, there are often several transportation options to consider. This work examines the impact of information access on attitudes about transportation options for this type of travel, using automobile, intercity bus, and passenger rail.This research uses a data set compiled from a travel survey conducted for trips from Northern New England to four major cities in the Northeast. The survey had questions on actual trips taken, a hypothetical trip to New York City, and attitudes about traveling by automobile, intercity bus, and passenger rail. The sample was split into two groups, with and without access to an intercity travel planning web tool, designed with this survey. The tool had scheduling options for travelling to New York City by intercity bus or rail.  So far, this research has included reviewing the literature, exploring the data set, and developing research questions. One question is: What impact does access to information have on people’s attitudes about traveling from Northern New England to major cities in the Northeast by automobile, intercity bus and passenger rail? Differences in survey responses between the two groups are being considered, to identify and measure the possible significance of information access on the outcome of a variety of questions related to this type of intercity travel. Descriptive statistics will be presented for the data set. The two study groups are being evaluated for preexisting bias. The goal is to better quantify impacts of access to information on attitudes about traveling from Northern New England to major cities in the Northeast by automobile, intercity bus and passenger rail.

Paola Rekalde Aizpuru
TRC Graduate ScholarCivil Engineering
Teenagers’ mode choice to and from school, and technology use for transportation: Analysis of students from five high schools in Vermont and California:

The carhops and drive-ins of the 1950s are symbolic of the freedom that the automobile has granted Americans. What the general public has gained from the automobile, however, may come at the expense of independent mobility and choices for today’s adolescents, particularly those not yet old enough to drive or those from lower income families. Sprawl land use development patterns and limited transportation choices in most American cities often hold teenagers and their chauffeuring parents captive to the automobile. At the same time, information and communication technology is fast evolving and changing the ways in which teenagers live, interact, and communicate with others; easier transportation coordination is one potential outcome. This study seeks to examine teenagers’ travel behavior for their most common destination – going to and from school – and how the use of technology influences this behavior. Survey data from five high schools, three in Northern California and two in Vermont, are used to identify the mode choice to and from school, socio-demographic characteristics, and technology use of the sampled teenagers. The built environment of the teenagers’ home surroundings is determined by data obtained from the 2010 Census. Logistic regression analysis is used to describe the most significant variables influencing both mode choice to and from school, and the factors associated with the use of technology. Preliminary findings show that having a driver’s license and access to a car, being an older adolescent, and traveling longer distances to school are factors that may positively correlate with driving to/from school. Conversely, living in higher density neighborhoods and closer to schools may be related to walking and biking to/from school. Interestingly, mode choice behavior does not appear to significantly vary between high schoolers from Northern California and VT.

Fatemeh Sadeghpoursotobadi

TRC Graduate Scholar

Civil Engineering


 The impact of network and demand disaggregation on modeling transportation system resiliency measures:

The impact of network and demand disaggregation on modeling transportation system resiliency measures  The highway transportation system in the United States was used more than 4.2 million passenger-miles and 2.3 billion freight ton-miles in 2012[1]. Any disruption in the system, whether natural, human-caused, intentional or unintentional, can have a significant impact on society in terms of the economy, safety, security and the environment. It is necessary to develop strategies to prevent such events, minimize their impacts and protect the most critical elements of the system. To prioritize the most critical segments, one needs to model operations the transportation system under normal conditions and with disruptions. In this study, we focus model the network robustness of individual road links by considering link capacity reduction and using the known travel demands between the origin and destination (OD) zones in the network.  This paper will investigate two questions. First, how detailed does the network model need to be so as to analyze accurately assess criticality of the links? It is common practice in the industry to only model main arterial highways for planning purposes or congestion management. However, less major roads provide redundancy to major roads affecting their relative criticality. Similarly, most models use aggregate zone-based OD matrices, where each element Tij in the matrix shows the number of trips from origin i to destination j. The second question in this paper is how the accuracy of the measures of relative link criticality is impacted by the spatial aggregation level of the OD matrix. To address the above questions, we use one hypothetical regional road network (148 links and 128 miles), and the road network of Chittenden County, Vermont (population 156000, 619 square miles, 8000 links). The rank order of importance or criticality for links in the networks are calculate based on Network Robustness Index (NRI) method which repeats user equilibrium traffic assignment while disrupting individual link capacities one by one. Changes in rank order between different cases if model aggregations are compared by using Spearman’s correlation coefficient.  (1. Bureau of Transportation Statistics. US Department of Transportation. Retrieved 5 December 2014.)

Flora Su

Civil Engineering

Poster 19B

Quantification of Gas-Phase Species in Biodiesel Exhaust Emissions using Fourier Transform Infrared (FTIR) Spectroscopy: 

The push  for  renewable  energy  has  led  to  increasing  popularity  in  biodiesel  use  in  place  of petroleum  diesel.  While  known  to  reduce  most criteria air  pollutants, studies  have  shown  that biodiesel  combustion  may  increase mobile  source  air  toxics  (MSATs)Emissions.  The effect of biodiesel use on MSAT emissions remains largely inconclusive.  Some studies suggest that carbonyl emissions (a type of MSAT) may increase due to the oxygenated nature of biodiesel fuel, while others claim that biodiesel combustion can reduce carbonyl emissions. This project focused on identifying how  biodiesel  fuel  content (Bxx) and engine load affected emissions of criteria pollutants and MSATs, which were quantified using FTIR spectroscopy. Infrared spectra collected at  the University  of Vermont from  June – October  2013  of waste  vegetable  oil  (WVO) biodiesel exhaust for B0, B10,  B20, B50, and  B100 blends were  reprocessed using MKS MultiGas 2030 High Speed software for CO, CO2, NOx, and  21 air toxics, including formaldehyde. The analysis found  that of the  MSATs, formaldehyde  was  present  in  the highest  concentrations,  while other MSATs were detected in very  small  quantities  or  were  not measured consistently above the detection  limit. Thus  only  formaldehyde  provided  sufficiently  reliable  data  for  observing  the effects of biodiesel fuel content and engine load on MSAT emissions. Emissions for products of incomplete combustion (CO, formaldehyde) decreased with increasing engine load, as well as with higher Bxx. CO2 emissions increased with higher engine load, but were not significantly affected by Bxx. At low engine load, NO emissions decreased with increasing Bxx, but were not affected at higher engine loads. NO2 emissions decreased with increasing Bxx at higher engine loads, but were not affected by biodiesel at lower engine loads. Future  work  to  investigate spectral interference  between  carbonyls should  be  conducted  to  improve  the  application  of  FTIR  to biodiesel exhaust analysis.

Posters 2:00-3:30p Title/Details Video|PDF
Olivia Taylor

Environmental Studies


The relationship between gas prices and transit ridership trends in Vermont by county from January 2004 to December 31, 2013:

For my Honors Thesis, I researched gas price and transit ridership data in the rural state of Vermont by county in the time period from January 2004 to December 31, 2013. My research has addressed the topic of understanding transit ridership, specifically in rural or micropolitan areas. Previous literature suggests that there is a lack of research on the relationship between transit ridership and gas prices in rural areas.  I have collected monthly ridership data from the various transit authorities around Vermont, and have taken into account fare changes, as well as additions of buses or bus routes within the time period.  Using SPSS and Excel, I have analyzed the monthly ridership Data with monthly gas price data in order to determine their relationship.I have discovered a significant correlation between public transit ridership and gas prices in both urban and rural counties in Vermont. However, there is a more significant correlation in urban counties then in rural, as expected.  Additionally, I found the correlation became more significant once I lagged the gas price data. Using population density and information about each transit authority, I will be making claims about the effects of gas prices in Vermont on public transit ridership by county. In conclusion, I believe Vermont should adjust its gas tax in order to incentive the use of public transit in more urban counties where there is greater access to public transit.

Session VI 3:00-3:45 Presentations Title/Details Video|PDF

Environmental Studies

ROOM Chitt Rm 413

Analyzing Bicycle Routes and Forecasting Effective Development for Burlington, VT:

This paper describes pathway analysis and assessment of travel behavior for cyclists in Burlington, VT. This research used a survey method to collect pathway usage and route selection data. Respondent’s most frequently used bicycle route was modeled using Geographic Information Systems (GIS), and stated preference data was analyzed to assess patterns in route selection. Infrastructure, trip distance, street connectivity, automobile traffic, geography and bicyclist typography were all considered. This research’s data is derived from 119 survey responses that were collected in June and July of 2015. The results of this research is combined with conclusions derived from existing research in order to forecast where in Burlington, VT investment could reap the most utility.

Benjamin Kaufman

Environmental Studies

ROOM Chitt Rm 413

Bike Lane Impacts on Driver Speeds:

Do you ever find yourself slowing down because of bikers on the road? Are you afraid that the growing biking coalition will impact your commuting time? This research project presents an analysis of the impacts of bike lanes on average driver speeds on Burlington roadways, as well as the impact of cyclist presence on speed of traffic.


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