Research and Publications - Alabama Transportation Institute
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Item 2018 Transportation Midterm Election Results(2019-09) Mozayen, BouranItem A low-cost approach to identify hazard curvature for local road networks using open-source data(Elsevier, 2021-06) Hu, Qinglin; Li, Xiaobing; Liu, Jun; Adanu, Emmanuel KofiVehicle crashes are a leading cause of death in the United States. Curvature in local roadways has been identified as one of the most significant factors that lead to fatal crashes. Given the large number of local roads and their relatively low traffic volume ‐ compared with interstates or freeways ‐ most local roads may not receive priorities in the first phase of highway upgrades, and critical locations, e.g., sharp curves (vertical and/or horizontal), in the network may be a deadly threat for both advanced autonomous vehicles and conventional vehicles. Furthermore, identifying local roadway curvatures presents various obstacles, such as high budgets and lack of survey data. To fill this gap, this study offers a low‐cost approach to constructing three‐dimensional geometric profiles for local roads in a relatively large study area using open‐source data. Given these profiles, critical road segments, including extreme horizontal and vertical curves and their combinations, can be identified. This study re‐classifies the local road segments into 20 sub‐categories based on the calculated vertical grades and curve radii and incorporates those segments into a zero‐inflated native binomial model for crash occurrence. Model results showed that grades or curves were associated with decreased crash frequency compared with straight and flat roads. However, segments with larger horizontal curve radii and low grades were found to be associated with increased crash frequency. Further implications are discussed in the paper.Item A Predictive 0-D HCCI Combustion Model for Natural Gas, Ethanol, Gasoline, and Primary Reference Fuel Blends(2018-10-13) Zhou, Yingcong; Hariharan, Deivanayagam; Yang, Ruinan; Mamalis, Sotirios; Lawler, BenjaminHomogeneous Charge Compression Ignition (HCCI) is a promising advanced combustion concept with high thermal efficiency and low exhaust emissions. This work purposes a computationally-efficient, zero-dimensional (0-D) HCCI combustion model that does not need to solve any differential equations. To develop the burn rate correlations, experimental HCCI data of ethanol, natural gas, E10-gasoline, and Primary Reference Fuel (PRF) blends was collected on a CFR engine. The burn rate model is built based on the individual cycle mass fraction burned (MFB) curves calculated from the experimental data. CA0 can be predicted from an ignition delay correlation. Once CA0 is known, CA50 and CA90 can be predicted based on CA0 and the charge-mass equivalence ratio . Then, with CA0, 50 and 90 known, a Wiebe function can be constructed to represent the MFB curve and burn rate. For PRF blends, low-temperature and high-temperature heat releases (LTHR and HTHR) are modeled by two Wiebe functions with and PRF number dependence. The fitted model has high accuracy compared to the experimental data with R2 values generally greater than 0.97. Finally, various ignition delay correlations from the literature are also tested against the experimentally collected data and some modifications to the correlations are suggested.Item Addressing Alabama’s Transportation Infrastructure: Roads and Bridges(Alabama Transportation Institute, 2019) Nambisan, Shashi; Smyth, Justice; Polunsky, Steven; Adanu, Kofi; Hainen, Alex; Hudnall, Matthew; Ijaz, Ahmad; Lidbe, Abhay; Liu, Jun; McNamara, Maggie; Penmetsa, Praveena; Tedla, Elsa; Turner, Dan; Wang, Teng; Ellis, David; Lomax, Tim; Glover, Brianne; Boroweic, Jeff; Huntsman, Brett; Koeneman, Pete; Kuzio, Jacqueline; Schrank, David; Steadman, Max; Wang, TengxiIn the year 2040, Alabamians will take stock of their transportation network and how it provides for economic growth and quality of life. They will look back on decisions made in 2019 by Alabama’s citizens, business community, and elected leadership. At the time of writing this report (2018), exotic and disruptive innovations such as self-driving vehicles, networked ridesharing, cars and trucks communicating electronically with each other and the roadside, and unmanned aerial, marine, and terrestrial vehicles are moving through research and development phases into real-world testing and eventual deployment. Regardless of their future promise or impact, infrastructure demand for the next 20 years is expected to be overwhelmingly focused on well-constructed and maintained roads and bridges with sufficient capacity and consideration for safety to enable efficient freight and passenger movement across the state. This report examines the extent, condition, and use of the Alabama road network. The authors received input from a wide range of stakeholders, including legislators, residents, the business community, shippers, truck and auto drivers, passengers, and others involved in the development and use of the network.Item Alabama Road Bid Bundling Authority(2019-10) Fisher, JustinItem An Analysis of the Effects of Crash Factors and Precrash Actions on Side Impact Crashes at Unsignalized Intersections(Wiley, 2021) Adanu, Emmanuel Kofi; Li, Xiaobing; Liu, Jun; Jones, StevenAnnually, side impact crashes contribute to a significant proportion of road fatalities. These crashes typically occur as a result of traffic violations at intersections. This study contributes to efforts in addressing side impact crashes at unsignalized intersections by performing a path analysis to unravel some behavioral trajectories through which these crashes occur. The study further investigated how these behavioral pathways influence the severity of the crashes. Crashes that occurred at unsignalized four-way intersections and T-junctions in Alabama were used for model estimations. Three precrash actions, failed to yield right-of-way at the stop sign, failed to yield right-of-way at a turn, and running stop sign, were considered. +e model estimation results reveal that some of the crash factors were more associated with certain precrash factors but not others at either four-way intersections or T-junctions or both. It was observed that side impact crashes that occurred under daylight conditions at four-way intersections, for instance, were less likely to involve running a stop sign but more likely to involve failure to yield at the stop sign and failure to yield right-of-way at a turn, but under dark and unlit roadway conditions, the at-fault drivers were more likely to run a stop sign or fail to yield at a stop sign but less likely to be involved in failure to yield right-of-way at a turn. +is approach to injury severity analysis uncovers complex underlying relationships between precrash actions, other contributing factors, and crash outcomes.Item An Assessment of Alabama’s Electric Vehicle Charging Infrastructure and Policies: Identiyfing Gaps and Needs(2020-01) Bredikhina, Olga A.; Fisher, Justin; Hockstad, Trayce; Mozayen, Bouran; Rafique, Sanaa; Wheeler, MelissaItem Analysis of Distracted Driving in Alabama 2012-2016 Data(2017-06) Brown, David B.; Stricklin, RhondaItem Analysis of Fatal Crashes in CY2016 as Compared to CY2014(2017-08) Brown, David B.; Stricklin, Rhonda; Norris, JesseItem Analysis of Motorcycle Caused and Motorcycle Victim Crashes CY2010-2014 Data(2015-10-23) Brown, DaveThis report has the objective of presenting a problem identification that was done on motorcycle (MC) crashes with the goal of establishing and improving countermeasures for reducing these crash frequencies and severities in the future.Item Analysis of Speed-Related Crashes in CY2012-2016(2017-09) Brown, David B.; Stricklin, Rhonda; Norris, JesseItem Analysis of the Most Critical Factors in Young (16-20 Year Old) Driver-Caused Vehicle Crashes(2017-10-08) Brown, David B.Item Analysis of Vehicle Defective Brakes and Tires(2020-02-15) Brown, David B.Item Automated Unity: Evaluating the Uniform Law Commission's Autonomous Vehicle Act(Washburn University School of Law, 2021-01) Hockstad, Trayce; Fisher, JustinItem Autonomous Vehicle Definitions in SEC States(2019-06) Transportation Policy Research CenterItem Autonomous Vehicles: Overview of Federal and Alabama Statute and Regulation(2019-11) Bredikhina, Olga A.Item CARE IMPACT Study COVID vs Normal Times(2020-07-28) Brown, David B.Item CARE IMPACT Study Failure to Yield and Ran (FtY)(2020) Brown, David B.Item CARE IMPACT Study of Age 0-15 Year Old Occupants(2019-07-24) Brown, David B.Item CARE IMPACT Study of Railroad Involved Crashes(2020-06-29) Brown, David B.