Compendium of Student Papers: 2015 Undergraduate Transportation Scholars Program

Michelle Anderson, and Katherine A. Foreman, Authors, and H. Gene Hawkins, Editor, September 2015

This report is a compilation of research papers written by students participating in the 2015 Undergraduate Transportation Scholars Program. The 10-week summer program, now in its 25th year, provides undergraduate students in Civil Engineering the opportunity to learn about transportation engineering through participating in sponsored transportation research projects. The program design allows students to interact directly with a Texas A&M University faculty member or Texas A&M Transportation Institute researcher in developing a research proposal, conducting valid research, and documenting the research results through oral presentations and research papers.

The papers in this compendium report on the following topics: 1) Traffic Safety Issues and Commercial Motor Vehicle Crashes: A Case Study in the Eagle Ford Shale; and 2) Differences Between Familiar and Unfamiliar Drivers.

Keywords: Commercial Motor Vehicles, Vehicle, Crash, Driver’s Behavior

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High Speed Rail Distribution Study

Carol Abel Lewis, Ph.D., Latissha Clark, Grace Asanaenyi, Wu Ying, August 2016

The Texas Central Partners are in the process of developing a high speed rail line connecting Houston and Dallas, Texas. Ultimately, plans are for 8 car trains that accommodate 200 people per vehicle scheduled every 30 minutes. In addition, Texas Department of Transportation (TxDOT) and officials in Austin, Houston and San Antonio are investigating intercity (interregional) rail to provide frequent rail service linking those cities. After arriving, passengers will need disbursement throughout the cities from the rail terminal station. The menu of options includes passenger pick-up (private by a friend or relative or purchased through a provider), taxi/limousine, rental car or public transportation. This research investigates the distribution patterns of northeastern cities with a history of intercity ground transportation as well as distribution patterns from a Houston area airport to assess the potential modal choices of passengers disembarking from intercity rail systems in Texas. In addition, a gravity formula is applied to several employment/activity locations to anticipate patrons’ distribution choices. The research focuses on the proposed location for the high speed rail terminal.

Keywords: First Mile, Last Mile, Transit Connectivity

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Quantification of Infrastructure Consumption under Different Axle Configurations and Wheel Loads

Ambarish Banerjee, Maria Burton, and Jorge Prozzi, January 2016

Recent developments in the energy sector in Texas, in particular oil, gas and wind energy, have resulted in increased volumes of traffic generated in areas such as the Barnett Shale, Eagle Ford Shale, Permian Basin, the Texas Panhandle, and others. In the case of oil and gas, the development and operation of a well site requires significant number of truck movements (including oversize/overweight loads) that accelerate the deterioration of the surface transportation network of the state faster that what was designed for. This unanticipated and accelerated deterioration of the road network imposes additional burden on already insufficient maintenance and rehabilitation budgets that affect most state highway agencies in the United States. The energy sector contributes immensely to the economic competitiveness of the State of Texas and the Southwest Region of the United States, but, under the present situation, the Texas Department of Transportation (TxDOT) does not have the necessary resources to keep up with reconstruction, rehabilitation or maintenance of the system to keep it safe for the general public. A solution has to be worked out to address this immediate problem.

Keywords: Oversize, Overweight, Trucks, OS/OW, Equivalent Damage Factor, EDF, DARWin-ME, Load Equivalency

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Analysis of Evacuation Clearance Time under Megaregion Disaster Threats

Zhao Zhang and Brian Wolshon, January 2016

The significance and continuous growth of urbanized areas throughout the world has led to the emergence of the global phenomenon of megaregions. Megaregions often share common historical, cultural, environmental, and topographic/geologic systems as well as close economic ties, facilitated by transportation linkages that connect the movement of people and freight. Another characteristic that megaregions also often share are threats from naturally-occurring and manmade disasters. This paper describes a project to better understand, prepare for, and respond to catastrophic disasters in megaregions In the research, a mass evacuation of the United States Gulf Coast megaregion was modeled based on past hurricane scenarios in the area. The results of the analyses revealed how operational characteristics of the megaregion road network vary and how strategies such as temporally-phased evacuations and regional contraflow operations are able increase overall system effectiveness. The results of the simulations also showed numerous limitations of the network as well as existing modeling and computational processing capabilities to create such simulations.

Keywords: Megaregion, Evacuation, Simulation, Modeling, Regional Planning

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Gulf Coast Megaregion Evacuation Traffic Simulation Modeling and Analysis

Zhao Zhang and Brian Wolshon, December 2015

This paper describes a project to develop a micro-level traffic simulation for a megaregion. To accomplish this, a mass evacuation event was modeled using a traffic demand generation process that created a spatial and temporal distribution of departure times, origins, and destinations based on past hurricane scenarios. A megaregion-scale simulation was required to assess this event because only at this level can traffic from multiple cities, over several days, with route assignments in multiple and overlapping directions be analyzed. Among the findings of the research was that it is possible to scale-up and adapt existing models to reflect a simultaneous multi-city evacuation covering a megaregion. The movements generated by the demand and operational models were both logical and meaningful and they were able to capture the key elements of the system, including the traffic progression over vast spaces and long time durations. They were also adequate to demonstrate benefits of proactive traffic management strategies and the effect of increased and decreased advanced warning times. The project also revealed numerous limitations of existing modeling and computational processing capabilities. The knowledge and results gained from this research can be adaptable and transferable for the evaluation of other locations with different road networks, populations, transportation resources, and hazard threats. Models such as this can be modified to represent anticipated growth and development within large regions and can be used to evaluate the interrelationships between behavioral response and regional transportation management strategies.

Keywords: Megaregion, Evacuation, Simulation, Modeling, Regional Planning

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Project Consistency with Transportation Plans and Air Quality Conformity Workshops

Reza Farzaneh, Megan Kenney, and Jolanda Prozzi, April 2015

This implementation project supports streamlined project delivery, one of the goals outlined by the Texas Department of Transportation (TxDOT) leadership to achieve an efficient and effective transportation system in Texas. The project benefits TxDOT divisions, districts, and metropolitan planning organizations during the project development process. This project was developed to help TxDOT implement the findings of TxDOT Project 0-6758: Maintaining Project Consistency with Transportation Plans throughout the Project Life Cycle with an Emphasis on Maintaining Air Quality Conformity. The research team organized and conducted four training workshops in Houston, El Paso, and Dallas District offices; and at the 2014 TxDOT Environmental Conference in Galveston. In addition to the training slides, the participants received the Project Consistency Guidebook, which documents procedures, tools, and recommendations to prevent and address project inconsistencies throughout the project development process. The research team collected and documented feedback from the participants. Researchers then finalized the training materials based on workshop feedback. The research team submitted the final training materials to TxDOT’s Human Resources Training Program for inclusion in the TxDOT employee training catalog and the TxDOT iWay training system.

Keywords: Project Development Process, Project Consistency, Transportation Planning, Transportation Conformity, Project Delay, Project Communication

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Cost-Effectiveness Analysis of CNG Urban Taxi Operations

Mark A. Euritt, October, 1993

Increased emphasis on energy efficiency and air quality has resulted in a number of state and federal initiatives examining the use of alternative fuels for motor vehicles. Texas’ program for alternate fuels includes compressed natural gas (CNG). Based on an analysis of 30-year life-cycle costs, CNG is a cost-effective option for high-mileage taxi operations. High mileage is defined as at least 83,586 miles (134,573 km) for a fleet of 5 taxis, 35,769 miles (57,588 km) for a fleet of 25 taxis, and 30,193 miles
(48,611 km) for a fleet of 50 taxis. The largest fleet (50) generates an Internal Rate of Return on investment of 30 percent; 22.5 percent is realized for the medium (25) fleet, and 11 percent for the small (5) fleet. Availability of original equipment manufacturer (OEM) dedicated natural gas vehicles is vital to the future success of CNG taxi operations. OEM vehicles offer important efficiency gains needed to justify the purchase of CNG vehicles.

Keywords: Alternate Fuels, Energy Efficiency, Air Quality, Compressed Natural Gas (CNG), Vehicles, Life- Cycle Costs, Cost-Effective, High-Mileage (Urban) Taxi Operations, Fleet, Original Equipment Manufacturer (OEM), Analysis, Internal Rate of Return, Public Refueling

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Real-time Optimization of Passenger Collection for Commuter Rial Systems

Yao Yu, Randy Machemehl, and Shadi Hakimi, September, 2014

Commuter rail systems are being introduced into many urban areas as an alternative mode to automobiles for commuting trips. The shift from the auto mode to rail mode is anticipated to greatly help alleviate traffic congestion in urban road networks. However, the right-of-way of many existing commuter rail systems is usually not ideally located. Since the locations of rail systems were typically chosen long ago to serve the needs of freight customers, the majority of current commuter rail passengers have to take a non-walkable connecting trip to reach their final destinations after departing even the most conveniently located rail stations. To make rail a more viable, competitive commuting option, a bus feeder or circulator system is proposed for seamlessly transporting passengers from their departing rail stations to final work destinations. The primary research challenge in modeling such a bus circulator system is to optimally determine a bus route and stop sequence for each circulating tour using the real-time demand information. In this paper, we termed this joint routing and stop optimization problem the circulator service network design problem, the objective of which is to minimize the total tour cost incurred by bus passengers and operators while minimizing the walk time of each individual bus passenger. A bi-level nonlinear mixed integer programming model was constructed and a tabu search method with different local search strategies and neighborhood evaluation methods was then developed to tackle the circulator service network design problem.

Keywords: Transit Circulator Service, Leader-Follower Game, Bi-level Optimization Model, Combinatorial Optimization, Traveling Salesman Problem, Tabu Search

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Performance Measures for Multi-vehicle Allowance Shuttle Transit (MAST) System

Luca Quadrifoglio, Kai Yin, and Wei Lu, September, 2014

This study investigates the performance measures for multi-vehicle mobility allowance shuttle transit (MAST) system. Particularly, researchers were primarily concerned with two measures, waiting time and ride time, to evaluate the performance and help design of m-MAST systems. The MAST system is an innovative concept that allows transit vehicles to deviate from a fixed route consisting of a few mandatory checkpoints to serve on-demand customers within a predetermined service area, and thus can be both affordable and convenient enough to attract the general public. For the MAST system, the fixed route can be either a loop or a line between two terminals. The checkpoints are usually located at major transfer stops or high demand zones and are relatively far from each other. Researchers developed analytical results for the waiting time probability distribution and its expected value as well as the expected ride time for different types of customers in terms of the system parameters for both 1-MAST system and multi-vehicle MAST (m-MAST). Researchers also discussed the assumptions behind the estimation. Based on the analytical results, researchers provided the inherent constraints between these parameters and demand.

Keywords: Hybrid Transit, Analytical Modeling, Performance Measures

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Safety Performance for Freeway Weaving Segments

Yi Qi, Jie Liu and Yubain Wang, September, 2014

The intensive lane change maneuvers at weaving sections often result in safety and operational problems. Various factors, including the design of ramp roadways, use of auxiliary lanes, and continuity of lanes will have significant effects on the level of service and safety performance of the weaving sections. This study investigated the safety performance of freeway weaving sections and developed a quantitative model for predicting the safety impacts of different types of geometric treatments for freeway weaving sections. The results of this study show that weaving sections with longer length will have lower crash frequency per 1000 ft., more required lane changes for diverge vehicles will result in more crashes in the freeway weaving section, increasing merge traffic in the weaving sections will slightly reduce the crash risk at this section, and increasing diverge traffic in the weaving sections will increase the crash risk at this section. In this study, Crash Modification Factors (CMFs) were also developed based on the developed crash prediction model for estimating the impacts of different safety treatments for the freeway weaving sections.

Keywords: Freeway Weaving Section, Poisson Regression Model, Safety Performance, Crash Modification Factors (CMFs)

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Wetting Characteristics of Asphalt Binders at Mixing Temperatures

Patricia Hennig Osmari, Zelalem Arega, and Amit Bhasin, October 2013

Conventional hot mix asphalt (HMA) is produced by heating the aggregate and the asphalt binder to elevated
temperatures that are typically in the range of 150C to 160C. These temperatures ensure that the viscosity of the asphalt binder is low enough to effectively coat the aggregate particles. During the past decade, warm mix asphalt (WMA) has been introduced to reduce the mixing temperatures by approximately 30C compared to HMA. Workability at these reduced temperatures is typically achieved by the use of chemical additives in the asphalt binder or by foaming the asphalt binder using small percentages of water. The use of WMA is associated with advantages such as reduced emissions during mixture production, extended paving season and reduced aging in the asphalt binder. In case of the WMA and the HMA, one of the important physical properties that dictates the quality of coating is the surface tension of the asphalt binder at mixing temperatures. In this study, the surface tension of different liquid asphalt binders was measured at typical mixing temperatures. The effect of binder type, temperature, and chemical additives used to produce WMA on the surface tension of the binder was evaluated. Three different binders with and without three different chemical additives were used in this study. The dynamic surface tension was measured using four different rates of surface formation and at several different temperatures within the range of 140C and 170C. Results show that the surface tension of asphalt binder depends on the rate of surface formation, temperature and source of the asphalt binder. Dynamic surface tension of asphalt binders suggests that asphalt binders behave similar to surfactants. The addition of chemical warm mix additives did not significantly reduce the surface tension of the binder compared to the control.

Keywords: Warm Mix Asphalt, Hot Mix Asphalt, Workability, Surface Tension, Asphalt Binder

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Comparison of Fatigue Analysis Approaches for Hot-Mix Asphalt to Ensure a State of Good Repair

Amy Epps Martin, Edith Arambula, M. Emin Kutay, James Lawrence, Xue Luo, and Robert Lytton, October 2013

Fatigue cracking is a primary form of distress in hot-mix asphalt. The long-term nature of fatigue due to repeated loading and aging and its required tie to pavement structure present challenges in terms of evaluating mixture resistance. This project focused on comparing stiffness and fatigue life output from two recently developed approaches that use repeated direct tension tests: the Modified Calibrated Mechanistic with Surface Energy (CMSE*) approach and the Push-Pull Viscoelastic Continuum Damage (PP-VECD) approach.

The CMSE* and the PP-VECD approaches were applied to both laboratory and field specimens for two mixtures, one from SH 24 in the Paris (PAR) District and one from US 277 in the Laredo (LRD) District of the Texas Department of Transportation, and the results were compared. Both approaches can be used to characterize mixture fatigue resistance with relatively low variability. Based on stiffness, both approaches predict better resistance (lower stiffness) for the PAR mixture based on laboratory results but that the mixtures would have equivalent resistance based on field results for the CMSE* approach. There was also good agreement between laboratory and field specimens for the LRD mixture.

The two approaches define fatigue failure in different ways, and thus the rankings of mixture resistance may be different. For the CMSE* approach, the stiffer LRD mixture based on laboratory specimens results in a longer fatigue life, while for the PP-VECD approach, this mixture results in a shorter fatigue life. In addition, the PP-VECD approach outputs significantly lower fatigue lives than the CMSE* approach does due to differences in the analysis including critical strain values and accumulation of damage.

The CMSE* approach only requires a single test sequence, and thus fewer resources in terms of specimens and time are needed. However, the PP-VECD approach is more user friendly in terms of the analysis, and some of the required inputs (E*) can be used to evaluate mixture resistance to other distresses. Field specimens can be tested and analyzed using both approaches. Ultimately, the laboratory approach used should tie to field performance.

Keywords: Fatigue Resistance, Direct Tension Testing, Asphalt Mixtures, Push-Pull Testing

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Performance Analysis of Isolated Intersection Traffic Signals

Kai Yin, October 2013

This dissertation analyzes two unsolved problems to fulfill the gap in the literature: (1). What is the
vehicle delay and intersection capacity considering left-turn traffic at a pre-timed signal? (2). What are the mean and variance of delay to vehicles at a vehicle-actuated signal?

The first part of this research evaluates the intersection performance in terms of capacity and delay at an isolated pre-timed signal intersection.  Despite of a large body of literature on pre-timed signals, few studies have examined the interactions between left-turn and through vehicles.  In order to examine this missing part of study on the signalized intersection, two probabilistic models are proposed to deal with the left-turn bay blockage and queue spillback in a heuristic manner.  The second part of this research studies an isolated intersection with vehicle-actuated signal.  The actuated system dynamically allocates the green time among multiple approaches according to vehicle arrivals.  We develop a model to study the vehicle delay under a general arrival distribution with a given unit extension.  The model allows optimizing the signal performance over the unit extension.  The third part of this research applies graphical methods and diffusion approximations to the traffic signal problems.  We reinterpret a graphical method originally proposed by Newell in order to directly measure the variance of the time for the queue clearance at a signalized intersection.  Furthermore, we investigate the problems of disruptions occurred during a pretimed traffic signal cycle.  By diffusion approximation, we provide the quantitative estimation of the duration that the effects of disruptions dissipate.

Keywords: Traffic Signal, Isolated Intersection, Left-turn Traffic, Actuated Signal, Graphical Methods, Diffusion Approximation

ENTIRE DISSERTATION (Adobe Acrobat File – 18.5 MB)

A Methodology for Developing Performance-related Specifications for Pavement Preservation Treatments

Litao Liu, September 2013

Current materials and construction specifications for pavement preservation treatments are predominantly prescriptive and they have little or no methodical linkage between initial treatment quality and future performance.  There is an imperative need for performance-related specifications (PRS) that link the initial quality of pavement preservation treatments to their long-term performance and life-cycle costs so that rational pay adjustment and acceptance decisions can be made.  However, the current literature lacks a methodology for developing PRS for pavement preservation treatments.  The aim of this research is to fill this gap in the literature, with focus on thin HMA overlays.

In this dissertation, a novel approach was devised for developing performance prediction models for pavements that received preservation treatments.  In this approach, the model consists of two tightly-coupled components:   the first component is responsible for predicting the performance (e.g., IRI) of the existing pavement if no treatment was applied. The second component is responsible for predicting the reduction in pavement deterioration due to the application of the treatment. Inputs to the first component include material and construction properties of the existing pavement layers, climatic conditions, and traffic factors. Inputs to the second component include the treatment’s acceptance quality characteristics (AQCs), climatic conditions, and traffic factors.  The artificial neural networks (ANNs) and the Bayesian regression methods were used for developing the two model components.  Using this approach, a model was developed for predicting the International Roughness Index (IRI) of flexible pavement treated with thin HMA overlay.  The data used for developing and testing this model was obtained from the Long-Term Pavement Performance (LTPP) database. Artificial neural networks (ANNs) and Bayesian regression techniques were employed for developing the first and second components of this model, respectively.

A PRS methodology was developed for quantifying the difference between the initial quality levels of as-constructed and as-designed treatments. This methodology consists of a novel approach for determining the probability distributions of service life and present-worth value (PWV). This approach allows for transforming the probabilistic distribution of future IRI (predicted by the Bayesian model) into probability distributions for service life and PWV. Pay factors are then estimated based on the difference between the as-constructed and target PWVs. Finally, this dissertation provides insights into the relationships between initial quality (measured in terms of both mean and standard deviation of key acceptance quality characteristics) and expected pay factors through analysis of real world case studies of asphalt pavements treated with thin HMA overlays.

Keywords: Pavement Preservation, Performance-related Specifications, Performance Prediction Models, Life-cycle Cost Analysis

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Cycling in the African American Community:  Safety Training Guidelines and Findings

Talia McCray, Teri Durden, Eileen Schaubert, August 2013

This report is a program user’s manual for the Cycling in the African American Community (CAAC) safety training intervention.  The CAAC safety training intervention was designed to “nudge” more African Americans, who are often beginning cyclists or non-cyclists, to participate in a physical activity that promotes health and builds community.  One of the most cited reasons for not riding is that cycling is perceived as being unsafe.  The CAAC intervention attempts to address this issue through a carefully designed safety intervention that encompasses a pre and post survey, used in conjunction with an on-road cycling curriculum.  The report includes best practices for staging the intervention and analyzing outcomes.  Preliminary findings show that the safety training is significantly improving perceptions of cycling.

Keywords: Cycling, Transportation, Training, African Americans, Safety, Bicycle

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A New Spatial Multiple Discrete-Continuous Modeling Approach to Land Use Change Analysis

Subodh K. Dubey and Chandra R. Bhat, September 2013

This report formulates a multiple discrete-continuous probit (MDCP) land-use model within a spatially explicit economic structural framework for land-use change decisions. The spatial MDCP model is capable of predicting both the type and intensity of urban development patterns over large geographic areas, while also explicitly acknowledging geographic proximity-based spatial dependencies in these patterns. At a methodological level, the report focuses on specifying and estimating a spatial MDCP model that allows the dependent variable to exist in multiple discrete states with an intensity associated with each discrete state. The formulation also accommodates spatial dependencies, as well as spatial heterogeneity and heteroscedasticity, in the dependent variable, and should be applicable in a wide variety of fields where social and spatial dependencies between decision agents (or observation units) lead to spillover effects in multiple discrete-continuous choices (or states). A simulation exercise is undertaken to evaluate the ability of the proposed maximum approximate composite marginal likelihood (MACML) approach to recover parameters from a cross-sectional spatial MDCP model. The results show that the MACML approach does well in recovering parameters. An empirical demonstration of the approach is undertaken using the city of Austin parcel level land use data.

Keywords:  Spatial Econometrics, Multiple Discrete-Continuous Model, Random-coefficients, Land Use Analysis, MACML Approach

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Future Mobility Demand in Megaregions:  A National Study with a Focus on the Gulf Coast

Ming Zhang and Wenjia Zhang, September 2013

About three fourth of national population and wealth are concentered in the 11 megaregional areas that occupy one fourth of the land areas in the US. NHTS reveal that megaregions also concentrate current and future mobility demand. This report presents an approach that utilizes aggregate data for mobility study (for both passenger and freight) in a megaregional scale through a case study of the Gulf Coast megaregion (GCM). GCM exhibits unique travel characteristics relative to the national trend. A preliminary analysis on freight flow was also conducted for the GCM areas utilizing the 2002 and 2007 Commodity Flow Survey (CFS) data. The study shows that the GCM area would experience an enormous amount of mobility growth by year 2050. The per capita traffic volume generated by each traveler in 2050 would double the 2010 level. The total traffic volume in 2050 would grow much faster, four times higher than in 2010. Freight demand in the GCM area is also fast growing. The projected trends of future travel demand indicate a growing pressure on the transportation infrastructure in GCM. It is unlikely that the demand for high-speed travel can all be met by air travel. Accordingly, planning for megaregional transportation should seriously consider high-speed travel in the form of High Speed Rail (HSR) to accommodate the future travel demand in the GCM area.

Keywords: Travel Demand, Megaregion, the Gulf Coast Megaregion (GCM), High-speed Travel

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U in the Driver Seat – A Peer-to-Peer Pilot Program for Decreasing Car Crashes by College Students

Stacey M. Tisdale, April 2013

The goal of this project was to build a peer-to-peer (P2P) model targeted toward the college-age audience called “U in the Driver Seat” at two college campuses. We performed the following tasks:

• Conducted pre- and post-assessments of driving risk awareness and self-reported driving behavior;
• Performed field observations of seat belt use and driver’s use of electronic device(s);
• Established a leadership team at each campus;
• Provided safety messages and promotional items to the team;
• Provided ideas for project/safety messaging activities to the team;
• Assisted the teams in establishing a student-run designated driver program

Objectives of the study included:

• Gaining a better understanding of risk awareness and attitudes towards driving dangers;
• Measuring success of P2P messaging and activities for college-aged audience;
• Increasing understanding of safety messaging and design elements effective with this age group;
• Improving the program model

Keywords: Traffic Safety, Peer-to-Peer, College Program, Risk Awareness, Young Adult, Peer Leader

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Life-cycle Energy Implications of Different Residential Settings:  Recognizing Buildings, Travel, and Public Infrastructure

Brice Nichols and Kara Kockelman, August, 2013

The built environment can be used to influence travel demand, but very few studies consider the relative energy savings of such policies in context of a complex urban system. This analysis quantifies the day-to-day and embodied energy consumption of four different neighborhoods in Austin, Texas, to examine how built environment variations influence various sources of urban energy consumption. A microsimulation combines models for petroleum use (from driving) and residential and commercial power and natural gas use with rigorously measured building stock and infrastructure materials quantities (to arrive at embodied energy). Results indicate that the more suburban neighborhoods, with mostly detached single-family homes, consume up to 320% more embodied energy, 150% more operational energy, and about 160% more total life-cycle energy (per capita) than a densely developed neighborhood with mostly low-rise-apartments and duplexes. Across all neighborhoods, operational energy use comprised 83 to 92% of total energy use, and transportation sources (including personal vehicles and transit, plus street, parking structure, and sidewalk infrastructure) made up 44 to 47% of the life-cycle energy demands tallied. Energy elasticity calculations across the neighborhoods suggest that increased population density and reduced residential unit size offer greatest life-cycle energy savings per capita, by reducing both operational demands from driving and home energy use, and from less embodied energy from construction. The results support the notion that transportation and the built environment are strongly linked, and improving urban energy efficiency must come from policies and designs targeting embodied sources, not just a household’s travel and daily energy consumption.

Keywords:  Life-cycle Energy Use, Urban Systems, Neighborhood Design, Built Environment, Vehicle-Miles Traveled, Land Use Patterns, Sustainability Levers, Smart Growth

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Electric Vehicles and Public Charging Infrastructure:  Impediments and Opportunities for Success in the United States

Eric J. Borden and Leigh B. Boske, University of Texas at Austin, July 2013, 53 pp.

This report seeks to reach conclusions over the role that electric vehicles (EVs) and public charging infrastructure should play in the future U.S. transportation system As demonstrated in this report, electric vehicles are neither new nor technologically infeasible. Current circumstances have initiated what appears to be a revival of the EV – these circumstances include high oil prices, geopolitical instability, and growing awareness of environmental concerns resulting from conventional vehicles (CV) usage. Nevertheless, impediments remain. One of the most important is the prospect of building public charging infrastructure to allow drivers to use an EV like their conventional vehicle, for both long and short distances. Public charging infrastructure, however, cannot be built without some critical mass of EVs on the road to use them – otherwise they are not economically feasible. This report analyzes various facets of both EVs and public charging infrastructure to give the reader a clear understanding of the complex criteria that must be understood to assess EVs in the United States. Texas is given special consideration as a case study in this report, particularly the Austin area where public charging infrastructure for EVs is currently being implemented.

Keywords: Electric Vehicles, Charging Infrastructure, Economics, Case Study, Austin, Texas

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Development of an Interactive GIS Based Work Zone Traffic Control Tool

Jack Bringardner, Mason Gemar, and Randy Machemehl, University of Texas at Austin, August 2013, 90 pp.

The purpose of this study was to include consideration for intersections into the previously created GIS traffic control planning tool. Available data for making intersection control calculations were collected and integrated into the design of the tool. The limitations created by required assumptions were addressed, as well as more advanced techniques for overcoming these problems. The tool can be used to estimate capacity calculations at any signalized intersection within the NCTCOG modeling region. These calculations can be used to inform users about the effects of a construction plan. Inputs for using dynamic traffic assignment to further understand these effects is then addressed, focusing on the development of a subnetwork to reduce computation time for multiple temporary traffic control plans.

Keywords: Network Modeling, Subnetwork Selection, Capacity Estimation, Dynamic Traffic Assignment, DTA, Traffic Control Plans

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Simulation of Investment Returns of Toll Projects

Weiyuan Yuwen and Zhanmin Zhang, University of Texas at Austin, August 2013, 53 pp.

This research develops a methodological framework to illustrate key stages in applying the simulation of investment returns of toll projects, acting as an example process of helping agencies conduct numerical risk analysis by taking certain uncertainties associated with toll projects into consideration. The numerical financial model provides a deterministic financial evaluation for the project. Next, there are four risk sources identified in this research, including project-based risks, cost-based risks, toll-based risks and finance-based risks. For each risk source, critical variables are recognized and probability distributions are suggested. The deterministic financial evaluation result is obtained through the projected single-value estimates of these variables. By considering the variability associated with the components of a project, the Monte Carlo simulation technique is used to estimate the overall project risks. Risk simulation results are interpreted through various numerical measures of project’s risks, which further provide agencies with quantitative information to set investment decision criteria. For risk optimization, exploration of optimal value-combination of variables and utilization of single-variable control method are discussed, which could assist agencies in setting threshold toll prices in order to achieve the goal revenue and maximize potential returns on the investment. The risk analysis, consisting of risk simulation and risk optimization, can give the statistical distribution of investment returns for a project under analysis, providing decision makers with a direct approach to the evaluation of the projects’ financial risks and the development of recommendations for risk control measures.

Keywords:  Public Private Partnership, Risk Analysis, Financial Evaluation, Toll Projects

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Compendium of Student Papers: 2012 Undergraduate Transportation Scholars Program

H. Gene Hawkins, editor, Texas A&M University, May 2013, 56 pp. (600451-00003-1)

This report is a compilation of research papers written by students participating in the 2012 Undergraduate Transportation Scholars Program.  The 10-week summer program, now in its 22nd year, provides undergraduate students in Civil Engineering the opportunity to learn about transportation engineering through participating in sponsored transportation research projects.  The program design allows students to interact directly with a Texas A&M University faculty member or Texas A&M Transportation Institute researcher in developing a research proposal, conducting valid research, and documenting the research results through oral presentations and research papers.

The papers in this compendium report on the following topics: 1) Analysis of Factors Influencing Run-off Road Crashes on Horizontal Curves; and 2) Impact of Nighttime Work Zone Lighting on Motorists’ Detection of Objects.

Keywords: Safety, Traffic Control Devices, Curves, Work Zones, Illumination

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