Project Abstracts: 2007 to 2008
Transportation Systems and Materials
Non-Conventional Alternative Intersection Treatments Guide. J.E. Hummer. Vanasse Hangen Brustlin, Inc. 08/06 to 08/08
Heavy traffic flows at intersections present challenges to engineers regarding excessive delays and worsening safety performance. Major side effects also include pollution, wasted fuel, increased stress levels, and economic losses. Several innovative intersection designs that divert left turn movements and reduce signal phases have been studied by researchers and implemented by users, including continuous flow intersections, median u-turns, and superstreets. This study sponsored by the FHWA is to develop an informational guide for those designs that includes a design selection procedure, coverage on operational issues, geometric design considerations, pedestrian accommodations, safety estimations, cost assessments, and marketing materials.
Pavement Marking Performance Analysis. J.E. Hummer and W. Rasdorf. NC Department of Transportation. 7/07 to 06/09
With an investment of $1 million after five years of data collection, the NCDOT requested that NCSU develop a pavement markings research plan in order to analyze relationships between pavement marking retroreflectivity values and variables such as marking color, marking age, pavement surface, and AADT. Understanding retroreflectivity performance over time is important to establishing a pavement marking strategy that maximizes the material's service life and minimizes the replacement of pavement markings that still have sufficient retroreflectivity. Furthermore, this understanding will enable the NCDOT to implement management strategies that achieve the Federal standards for minimum pavement marking retroreflectivity.
Validation of APA Design Critera for Field Surface Mixtures. N.P. Khosla. NC Department of Transportation/FHWA. 08/04 to 12/09
Premature rutting of asphalt pavements is a serious concern experienced in recent years due to the increased traffic and wheel loads. Therefore, it is important to estimate the rutting potential of a mixture before construction. Several test methods are in practice to assess the rutting potential of a mixture. Of the different laboratory rut testers, the Asphalt Pavement Analyzer (APA) is the most widely used loaded wheel tester. Using the correlations between the results of APA and shear tests, this research project aims to validate and modify the rut depth criteria developed in the earlier project, by incorporating the test results of field surface mixtures.
Effect of the Use of Higher Percentages of RAP in NCDOT Hot Mix Asphalt. N.P. Khosla. NCDOT/FHWA. 07/07 to 06/09
The recycling of asphalt pavements has become a very routine procedure throughout the country. The use of higher percentages of RAP in construction would provide initial cost savings. However, a life cycle cost analysis is needed in order to determine whether use of higher percentages of RAP provides an economical advantage for the life cycle. In order to predict life cycle costs, the fatigue life and rut resistance of mixtures containing various amounts of RAP will be calculated from laboratory testing using the Simple Shear Tester (SST). Based on these results, the life cycle economic analysis can be completed and the optimum percentage of RAP can be determined.
Determining HMA Mix Design Methodologies for Predicting Fatigue Rutting Using Tensile Strength Testing. N.P. Khosla. NC Department of Transportation/FHWA. 07/07 to 06/09
During its lifetime, an asphalt concrete layer is subjected to many distress mechanisms: rutting, fatigue cracking, temperature cracking and moisture induced damage. Moisture damage of asphalt mixes, better known as stripping, is one of the major distresses affecting pavement performance. Since there is no strength criterion prescribed in the design of Superpave mixtures, an optimized value of tensile strength can be used as a good criterion in design of Superpave mixtures. This project aims at developing a mix design methodology using tensile strength testing of various asphalt mixtures as well as the correlations among the tensile strength and performance parameters of mixtures (fatigue and rutting).
Comprehensive Performance Evaluation of Polymer Modified Hot Mix Asphalt Mixtures. Y.R. Kim and R.H. Borden. Korea Kumho Petrochemical Co., Ltd. 10/06 to 10/08
With the goal of accurate pavement performance evaluation, the PI and his co-workers at NCSU have been developing advanced models for hot-mix asphalt (HMA) mixtures under complex loading conditons. Over the past decade, they have been successful in developing material models that can accurately capture various critical phenomena such as: microcrack induced damage this is critical for fatigue modeling; strain rate-temperature interdependence; and viscoplastic flow that is critical for rutting evaluation The resulting model is termed the viscoelastoplastic continuum damage (VEPCD) model.
Hot Mix Asphalt Performance-Related Specifications Based on Viscoelastoplastic Continuum Damage Models. Y.R. Kim and M.N. Guddati. DTFH61-08-H-00005, Federal Highway Administration. 02/08 to 02/12
Models developed at NCSU over the years provide a unique opportunity to develop a mechanistic Performance-Related Specification (PRS) for hot mix asphalt (HMA) mixtures. This project will focus on development of different analytical and experimental tools that can be used for the development of the HMA-PRS. The HMA-PRS will be hierarchical in nature; that is, a higher level specification uses more complete and accurate test and analysis methods, which requires more sophisticated testing.
Multiscale Modeling of Asphalt Concrete for Fatigue Cracking Evaluation. Y.R. Kim and M.N. Guddati. Texas A&M Research Foundation / FHWA. 12/06 to 11/11
Work at WRI-TTI-NCSU under previous funding directed by FHWA has developed continuum damage and micromechanics models of fatigue damage in asphalt mixtures/pavements. In the proposed study, these models will be refined and a wide range of materials and conditions will be tested. The primary objective of the proposed research is to understand the fatigue cracking phenomena in asphalt concrete at multiple scales from which material specifications and design methods would be developed.
Top-Down Fatigue Cracking of Hot-Mix Asphalt Layers. Y.R. Kim & M.N. Guddati. NCHRP 1-42A, Subcontract from University of Florida. 06/06 to 10/08
In this research, the viscoelastic continuum damage model implemented in the finite element program (VECD-FEP++) will be used to investigate the top-down fatigue cracking mechanism in hot-mix asphalt pavements. The VECD model and the dynamic modulus from the IDT test will serve as the primary experimental tools. The resulting VECD-FEP++ will be used to simulate the behavior of asphalt pavements with varying loading, environmental, and pavement factors. The results from the simulation will be investigated to develop mechanistic procedures to evaluate the top-down cracking propensity of asphalt pavement as a function of various factors and to predict the top-down cracking performance of asphalt pavement.
Calibration of Rutting Models for HMA Structural and Mix Design. Y.R. Kim and M.N. Guddati. NCHRP 9-30A, Subcontract from Applied Research Associates, Inc. 11/05 to 10/08
The objective of this research effort is to recommend revisions to the HMA rut depth prediction model in the mechanistic-empirical pavement design guide and software developed in NCHRP Project 1-37A for consideration by the NCHRP Project 1-40 panel and the AASHTO Joint Task Force on Pavements. The recommended revisions will be based on the calibration and validation of distress models with measured materials properties and performance data from existing field and other full-scale pavement sections that incorporate modified as well as unmodified asphalt binders.
Development of Multi-axial VEPCD-FEP++ and its Extension to Indirect Tension Test. Y.R. Kim and M.N. Guddati. Federal Highway Administration. 09/05 to 12/07
Over the past decade, the NCSU research team has been successful in developing HMA models that can accurately capture various critical phenomena such as microcrack induced damage, strain rate - temperature interdependence, and viscoplastic flow that is critical for high temperature modeling; the resulting model is termed the viscoelastoplastic continuum damage (VEPCD) model. The primary objectives of this research are to (1) extend the VEPCD model to multiaxial state of stress; (2) develop a three-dimensional finite element program with the multiaxial VEPCD model; and (3) extend the principles used in the VEPCD modeling to the indirect tension mode.
Investigation of Highway Asset Inventory and Data Collection Methods. NC Department of Transportation. Y.R. Kim, J. Hummer, M. Gabr, D. Johnston. 04/08 to 12/08
The North Carolina Department of Transportation (NCDOT) is co-hosting a National Workshop on Highway Asset Inventory and Data Collection in September 2008. Four infrastructure elements have been identified as the focal areas for the workshop: 1) pavements, 2) bridges, 3) geotechnical features and drainage, and 4) roadside appurtenances. To evaluate the accuracy of various asset data collection technologies, vendors for these technologies will be invited and will test selected test sections. Research is needed to develop an experimental design for the vendor testing, to perform ground truth testing of the test sections, and to analyze the data from vendors to compare against the ground truth measurements.
Quantifying the Benefits of Improved Rolling of Chip Seals. Y.R. Kim. NC Department of Transportation. 07/05 to 12/07
This research is aimed at "low hanging fruit," that is, relatively low cost changes in compaction procedures that could significantly improve the chip seal performance in North Carolina. The performance measures to be evaluated in this study include aggregate embedment depth, aggregate retention, skid resistance, bleeding, and rutting. The research approach utilizes the chip seal performance test methods that have been used and refined in the ongoing NC Department of Transportation HWY 2003-09 project, Optimizing Gradations for Surface Treatments. The experimental program involves both laboratory and field experiments.
Development of a Virtual Testing Module for an Undergraduate Course on Materials Design. Y.R. Kim. LITRE Grant, North Carolina State University. 01/06 to 08/07
The short-term objective of this project is to enhance the students' understanding of the behavior of asphalt concrete through virtual microstructure fabrication and virtual testing. The medium-term goals are to (1) help develop graduate-level asphalt materials courses into distance-learning courses and (2) help enhance student learning in other materials-related course in the department, and elsewhere in the university, state, and country.
Performance Based Analysis of Polymer-Modified Emulsions in Asphalt Surface Treatments. Y.R. Kim. NC Department of Transportation. 07/06 to 06/08
This project focuses on the performance evaluation of polymer-modified emulsions in asphalt surface treatments. Limited research and data exist on quantifying the overall performance of polymer-modified surface treatments and associated cost-effectiveness. This project will test the improvement in surface treatment performance resulting from modifying the emulsion with polymers and its cost-effectiveness, in addition to providing baseline performance information about standard surface treatments which will be most valuable in planning maintenance activities. Recommendations will be made on the selection of a proper surface treatment option based on existing pavement distress, traffic volume, and road functionality.
Local Calibration of the MEPDG for Flexible Pavement Design. Y.R. Kim. NC Department of Transportation. 07/06 to 06/08
The objective of this study is to calibrate the NCHRP 1-37A Mechanistic-Empirical Pavement Design Guide with local data by developing a material database using typical layer materials (HMA and unbound materials) for flexible pavements in North Carolina. The scope of research includes both fatigue cracking and rutting. The primary products of the proposed research are the flexible pavement layer materials performance database and the MEPDG HMA performance model coefficients for typical North Carolina HMA mixtures. An additional product will be an implementation plan with instructions for modifying the MEPDG to incorporate the local coefficients. This plan will shorten the delay between the research and the implementation of the pavement design.
Development of a New Chip Seal Mix Design Method. Y.R. Kim. NC Department of Transportation. 07/07 to 06/09
The objective of the proposed research project is to develop a new chip seal mix design method that can be applied to lightweight aggregate and polymer-modified emulsion as well as to normal aggregate and emulsion, and can be utilized efficiently by field personnel. This design procedure will utilize test methods that are currently under development at North Carolina State University (NCSU) with the objective of measuring important design parameters. The developed design procedure will be verified and calibrated through field experiments.
LTPP Computed Parameter: Dynamic Modulus. Y.R. Kim. FHWA. 09/07 to 04/09
The primary objective of this project is to develop estimates of the dynamic modulus (|E*|) of hot mix asphalt (HMA) layers on LTPP test sections following the models used in the Mechanistic-Empirical Pavement Design Guide (M-E PDG), for storage in the LTPP Pavement Performance Database.
Development of Traffic Data Input Resources for the Mechanistic-Empirical Pavement Design Process. Y.R. Kim, G. List, J. Stone, and W. Rasdorf. North Carolina Department of Transportation. 07/07 to 06/09
The Mechanistic-Empirical Pavement Design Guide for New and Rehabilitated Pavement Structures uses nationally based data traffic inputs and recommends that state DOTs develop their own site-specific and regional values. NCDOT recently completed an implementation plan for adopting the MEPDG, and two of the critical implementation recommendations addressed new data collection requirements for site-specific truck classification counts, truck axle load spectra, regional average seasonal adjustment factors, and forecasting methods for axle loads, as well as truck class volumes. This research project addresses these NCDOT traffic data and forecasting needs for implementing the MEPDG.
Quantifying Non-Recurring Delay on New York City's Arterial Highways. G.F. List. Region II University Transportation Research Center. 07/05 - 05/08
This project, originally started at Rensselaer in conjunction with J. Falcocchio (Polytechnic) and K. Ozbay (Rutgers), was intended to help New York State DOT better quantify and predict non-recurring delay for New York City's freeway network. A new, improved methodology was developed to predict non-recurring delay for principal locations and corridors. The methodology predicts this delay in a way that tracks to the causal factors: the type of incident, location, weather conditions, congestion, vehicle speeds, number of lanes and ramps involved, etc. The enhanced methodology, coupled with new input data based on an extensive data analysis, was successfully applied to an analysis of the City's freeway network.
Wireless Electronic Toll and Traffic Management . G.F. List. Region II University Transportation Research Center. 10/05 - present
This project, originally started at Rensselaer in conjunction with W. Wallace, is focused on advancing the state-of-the-art in technology that allows transportation system managers to observe the performance of their systems. Several wireless, solar-powered E-ZPassSM tag readers have been installed in Rensselaer County east of Albany. The units are being tested for their ability to detect passing traffic and operate under widely varying weather conditions.
Incident Management for Safe, Secure and Productive Transportation Systems. G.F. List. Region II University Transportation Research Center. 10/05 - present
This project, originally started at Rensselaer in conjunction with W. Wallace, is focused on assessment of incident management systems that are designed for and can be deployed by medium-sized regions comparable to the Albany area. The study works closely with the New York State Thruway Authority and the New York State Police to develop case studies in incident management. This includes review of operating plans and procedures and the how these agencies integrate their operations across multiple regional dispatch and traffic management centers.
Placement of Detection Loops on High Speed Approaches to Traffic Signals. G.F. List. NC Department of Transportation. 07/06 to 06/08
At high-speed, signalized intersections, the placement of detectors is critical for safe and effective operation. Well-placed detectors and carefully chosen signal timing parameters, such as yellow and all-red times, can reduce the likelihood of both right-angle and rear-end collisions as drivers on the main road deal with dilemma zone issues - whether to slow down and stop or continue through the intersection. This project will explore the best placement of detectors on such approaches through a two-pronged effort involving modeling and field testing of alternative configurations. Recommended practices will be developed based on the modeling and field test results and benefit-cost analyses.
North Carolina Truck Traffic Profiles. G.F. List, J.R. Stone, and B. Mei. NC Department of Transportation. 07/06 to 12/08
Better trip profiles are needed to understand the extent to which heavy trucks are using the state's various categories of highways, from rural secondary roads to urban interstates. Pavement and bridge engineers need a better sense of truck weights and axle spacings. Investment decision makers and planners need a better picture of truck volumes, trip distances, and weight distributions by highway class and route category. To help meet these needs, this project aims to create better truck trip flow profiles.
North Carolina Statewide Logistics Plan. G.F. List, R. Foyle (ITRE), J.E. Hummer, J. Stone, and B. Williams. NC Office of State Budget and Management. 01/08 to 12/08
This project, sponsored by the North Carolina State Office of Budget and Management, developed a statewide freight logistics plan for North Carolina. Co-contributors were J. Cameron and H. Canipe (Transtech) and Erik Stomberg (Hatch Mott MacDonald). Most importantly, the plan suggests legislative and regulatory actions to enable North Carolina to be more pro-active in facilitating commercial enterprises, goods movement and economic prosperity. It recommends creation of a freight logistics authority reporting to the governor that has bonding ability and an empowerment to make freight-related infrastructure investment decisions. It also recommends bold investments in the freight aspects of the interstate system, intermodal facilities, ports, and air freight through public-private partnerships.
In-Vehicle Energy and Emissions Information System (IVEEIS). H.C. Frey and N.M. Rouphail. National Science Foundation. 01/03 to 12/08
The key objectives of this research project are to (1) develop a micro-scale predictor of energy use and emissions that is deployable at the individual vehicle level in real-time; (2) identify, compare, and evaluate alternate energy use and emissions sampling/reporting schemes that are appropriate at the vehicle and network levels; (3) develop and test a prototype In-Vehicle Energy and Emissions Information System (IVEEIS); and (4) formulate and assess the utility of IVEEIS in developing transportation design and control measures aimed at energy and emission management policies.
Crossing Solutions at Roundabouts and Channelized Turn Lanes for Pedestrians with Visions Disabilities. Ron Hughes (ITRE) and Nagui Rouphail. UNC-CH, NCHRP 3-78. 01/04 to 01/09
The objective of this research is to produce recommendations for geometric designs, traffic control devices, and other treatments that enable pedestrians who are visually impaired to cross roundabouts and channelized turn lanes (CTL's) independently and safely. These recommendations should be suitable for inclusion in transportation-industry practice and policies, including the AASHTO Policy on Geometric Design of Highways and Streets and the FHWA Manual on Uniform Traffic Control Devices. Consideration should be given to the impact of the recommendations on all users of roundabout intersections, including occupants of passenger car and trucks, pedestrians (including pedestrians with vision impairments), and bicycles.
Regional Development, Population Trend and Technology Change Impacts on Future Air Pollution Emissions. N.M. Rouphail and H.C. Frey. U.S. Environmental Protection Agency STAR grant via University of North Carolina at Chapel Hill, and Center for Transportation and the Environment. 11/04 to 11/08
The research tests the hypothesis that smart-growth development patterns can significantly influence the quantity and location of direct and indirect emissions from mobile sources. The patterns of interest include the type of development and its location. We will develop a general method for exploring the leverage that smart-growth development patterns have on the spatial pattern and quantity of emissions from mobile sources. We will explore scenarios and chart the envelope of the effectiveness of smart growth as a means for reducing emissions. We will determine whether substantial emissions reductions are feasible with forecasts of the market penetration of smart growth.
Hillsborough Street Roundabout Modeling and Simulation. City of Raleigh. Granting Agency: Kimley Horn and Associates. N. Rouphail. 08/06 to 03/08
This study models the roundabout system proposed for initial implementation on two corridors on Hillsborough Street around Pullen and Horn. The modeling will be conducted in VISSIM and will be used to analyze alternative operations of the roundabouts under proposed designs. The team will provide recommendations to the prime contractor on specific pedestrian treatments to ensure safe and efficient operations on the proposed corridors. ITRE will host a Summit to discuss potential solutions, their implications, and additional modeling to be carried out. ITRE will also provide a summary report of the findings as mutually agreed upon by KHA and ITRE.
Pedestrian Safety Enhancement on Hillsborough Street Roundabout Corridor Project. U.S. Dept. of Transportation. N. Rouphail. Granting Agency: Southeastern Transportation Center - University of Tennessee. 06/07 to 04/08
This project will supplement an existing micro-simulation modeling effort for a proposed roundabout corridor on Hillsborough Street in Raleigh, NC. The matching funds will be used to conduct field research on pedestrian crossing safety features for the proposed design. This proposal builds on the calibrated micro-simulation models developed during work with the non-federal matching fund source, and enhance the existing models by incorporating elements of pedestrian safety. Through field data collection, model calibration, validation and extension, the project will evaluate proposed pedestrian safety treatments and will provide decision support to pedestrian safety researchers, roundabout designers, as well as the immediate stakeholders of the proposed corridor.
Blind Pedestrian Access to Complex Intersections, Phase II. N. Rouphail. National Institutes of Health. Direct Sponsor: Western Michigan University. 06/07 to 05/12
Pedestrians who are blind make crossing decisions based on information about predictable patterns of vehicular movement. This information is conveyed by traffic sounds and accessible pedestrian signals. At roundabouts, these strategies do not apply because traffic flows freely and often unpredictably. Pedestrians negotiate roundabouts at crosswalks located about one to three car lengths back from the circulating roadway. Splitter islands (medians) either raised like traditional traffic islands or simply painted on the pavement provide a pedestrian refuge midway through street crossings. This research develops and evaluates methods to improve locating, aligning and crossing of blind pedestrians at roundabouts.
Ubiquitous Transportation Network Modeling and Simulation. Seoul National University. N. Rouphail. 11/07 to 08/08
The primary goal of this project is to assess the impact and benefits of the ubiquitous transportation network. The objectives are: 1. Achieve good understanding of the proposed ubiquitous transportation network capabilities. 2. Articulate the functional performance measures 3. Develop the requirements in a traffic micro-simulation environment, 4. Develop an inventory of facilities, and their interface that will be implemented in simulation Facilities will be selected from the HCM and will comprise both uninterrupted and interrupted flow facilities, 5. Assess the impact of technology market penetration on the efficiency of the system.
Understanding the Contributions of Operations, Technology, and Design to Meeting Highway Capacity Needs. N. Rouphail. Strategic Highway Research Program-C05 Project. Direct Sponsor: Kittleson and Associates. 01/08 to 01/10
This research quantifies the capacity benefits of operations, design, and technology improvements at the network level. This will provide transportation planners with information and tools to analyze operational improvements and develop guidelines for sustained service rates. The methods will include integration of traffic and performance data from multiple sources and applications of new assessment methods to identify packages of strategies that can substitute for capacity additions. These will combine technological, operational and design approaches that will be validated with independent data. Guidance at the network level for planners and operational managers on how these approaches could be cost-effective will emerge.
Development and Evaluation of Methodological Framework for Real-World Vehicle Energy Use and Emissions Estimation at Multiple Temporal and Vehicular Scales. H.C. Frey and N.M. Rouphail. National Science Foundation. 05/08 to 05/11
Vehicle Fuel Use and Emissions (FU&E) have substantial national energy and environmental implications, but are confounded by intra/inter-vehicle variability and, therefore, require scientific inquiry to develop an improved basis for their characterization and management. The main objectives of this research are to: (1) quantify intra-vehicle variability in FU&E due to inter-driver variability, cold start, ambient conditions, and road grades; (2) develop FU&E models based on multiple levels of vehicle aggregation and multiple temporal scales; and (3) evaluate the interface of these models with transportation models and for use with real-time vehicle detection.
Effects of Prolonged Heating on the Asphalt-Aggregate Bond Strength of HMA Containing Liquid. A.A. Tayebali and D. Knappe. NC Department of Transportation. 07/06 to 06/08
The objectives of this research are to determine the effect of prolonged heating on (1) asphalt-aggregate bond strength and (2) the moisture sensitivity of asphalt mixtures. In particular, this study will first evaluate the performance of mixtures using the tensile strength ratio test (AASHTO T283), and second, study the effect of additive content and prolonged heating on the surface interaction between asphalt binder and aggregate.
Effect of Gradation on Predicted Performance of Aggregate Base Course. T.M. Evans and A.A. Tayebali. North Carolina Department of Transportation. 01/08 to 12/08
The primary objectives of this research are to evaluate the effect of aggregate gradation on the mechanical properties of the ABC materials; and to develop numerical model(s) based on the discrete element method (DEM) to predict mechanical properties with changes in gradation. The DEM models will also provide insight into the underlying micromechanics that may contribute to variations in material performance as a function of ABC gradation. It is anticipated that this research study will result in performance-related criteria that can be incorporated into the NCDOT Standard Specifications that are used for acceptance of ABC material for pavement structure.
CAREER: System-wide Traffic Condition Monitoring and State Estimation for Intelligent Transportation Systems. B. Williams. National Science Foundation. 06/02 to 11/07
This five-year research and education program involves the teaching and application of rigorous and robust statistical modeling techniques to the process of assessing and predicting traffic stream states based on remotely sensed traffic data in advanced traffic management systems. Research results will include improved real-time traveler information, more rapid incident detection and response, and enhanced information support for dynamic transportation system management.
Environmental Implications of Current Domestic Trends in Goods Movement. B.M. Williams and G.F. List. Center for Transportation and the Environment . (Prime Sponsor: US Department of Transportation). 03/05 to 08/07
This research project will assess the environmental implications of global and domestic freight trends with a primary focus on congested gateways, such as deep water ports and border crossings. The project results will include policy recommendations for addressing freight-related environmental issues in a manner that will "ensure goods move efficiently and effectively through our ports and freight hubs while protecting the environment."
Best Practices Guidebook for Greenhouse Gas Reductions in Freight Transportation. B. Williams and H.C. Frey. US Department of Transportation via Center for Transportation and the Environment. 08/05 to 08/07
This research project involves a comprehensive scan of the freight sector, including public and private sector players, to catalog the practices and programs that are being used to reduce greenhouse gas emissions in the goods movement. All transportation modes will be included. The final research product will be a best practices guidebook to be published and disseminated by the US Department of Transportation.
EPA Truck Anti-Idling Demonstration Project. A. Tazewell (NC Solar Center), H.C. Frey, and J.R. Stone. US Environmental Protection Agency. 02/06 to 08/08
The objective is to assess potential environmental benefits of heavy-duty diesel freight truck idle reduction technologies installed on trucks in NC. A key goal is to quantify actual grams per gallons emissions with a portable gas analyzer and compare this data with data extrapolated from an on-board data logger and fuel use with and without idle reduction technologies.
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