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Development Of An Improved Arterial Roadway Performance Reliability Methodology, Ernest Tufuor

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

The need for reliable performance measures of urban arterial roadways is increasing because of the rise in traffic congestion and the high value of travel time. Consequently, travel time reliability (TTR), which combines components of measures of central tendency and measures of dispersion of travel times, has recently received considerable research interest.

The basis of all TTR metrics is the travel time distribution (TTD). Estimating and forecasting arterial TTDs for TTR analysis is the focus of this dissertation. This dissertation proposes a new TTR methodology that is a marked improvement on recent TTR estimation and forecasting methodologies including the current …

Vehicle-To-Barrier Communication During Real-World Vehicle Crash Tests, Samil Temel, Mehmet C. Vuran, Mohammad M.R. Lunar, Zhongyuan Zhao, Abdul Salam, Ronald K. Faller, Cody S. Stolle

School of Computing: Faculty Publications

Vehicle-to-barrier (V2B) communication is expected to facilitate wireless interactions between vehicles and roadside barriers in next-generation intelligent transportation systems. V2B systems will help mitigate single-vehicle, run-off-road crashes, which account for more than 50% of roadside crash fatalities. In this work, the characteristics of the wireless channel prior to and during a crash are analyzed using orthogonal frequency division multiplexing (OFDM) techniques, which has been used in existing vehicular communication systems. More specifically, the performance of OFDM-based V2B links are measured in real-world crash tests for the first time. Three crash tests conducted at the Midwest Roadside Safety Facility, Lincoln, Nebraska, …

Crop Height Estimation With Unmanned Aerial Vehicles, Carrick Detweiler, David Anthony, Sebastian Elbaum

School of Computing: Faculty Publications

An unmanned aerial vehicle (UAV) can be configured for crop height estimation. In some examples, the UAV includes an aerial propulsion system, a laser scanner configured to face downwards while the UAV is in flight, and a control system. The laser scanner is configured to scan through a two-dimensional scan angle and is characterized by a maxi mum range. The control system causes the UAV to fly over an agricultural field and maintain, using the aerial propulsion system and the laser scanner, a distance between the UAV and a top of crops in the agricultural field to within a programmed …

Development Of A Test Level 3 Transition Between Guardrail And Portable Concrete Barriers, Robert W. Bielenberg, David Gutierrez, Ronald K. Faller, John D. Reid, Phil Tenhulzen

Department of Civil and Environmental Engineering: Faculty Publications

Road construction often requires that work zones be created and shielded by portable concrete barriers (PCBs) to protect workers and equipment from errant vehicles as well as to prevent motorists from striking other roadside hazards. For an existing W-beam guardrail system installed adjacent to the roadway and near the work zone, guardrail sections are removed so a PCB system can be placed. A study was done to develop a crashworthy transition between W-beam guardrail and PCB systems. Design concepts were developed and refined through computer simulation with LS-DYNA. Additionally, a study of critical impact points was conducted to determine impact …

Calibrating The Robertson’S Platoon Dispersion Model On A Coordinated Corridor With Advance Warning Flashers, Zhao Li, Laurence Rilett, Ernest Tufuor

Department of Civil and Environmental Engineering: Faculty Publications

Platoon dispersion (PD) is the foundation of traffic signal coordination in an urban traffic network. PD describes the phenomenon by which vehicles depart from an upstream intersection as a platoon and begin to disperse before they arrive at the downstream intersection. Recently, advance warning flashers (AWFs) have been applied in many high-speed corridors. There is a need to update the traditional PD model to include the effect of AWFs. This paper examines the traffic flow dispersion patterns when an AWF is present and tests the hypothesis that the AWF will affect PD on a coordinated signal corridor. Platoon vehicles, which …