Civil and Environmental Engineering Commons^™

Modeling Bus Dwell Time And Time Lost Serving Stop In China, Chao Wang, Zhirui Ye, Yuan Wang, Yueru Xu, Wei Wang

Journal of Public Transportation

The primary objective of this study was to develop a quantitative approach to estimate bus dwell time and time lost serving stop, which included acceleration and deceleration time, dead time, and time for serving boarding and alighting passengers. A polynomial model incorporating kinematics of a particle was derived for estimating bus acceleration and deceleration time. In addition, descriptive statistics methods were used to analyze dead time. A case study was conducted to show the applicability of the proposed model with data collected from the seven most common types of bus stops in China. R-square and Mean Absolute Percentage Error (MAPE) …

Public Transport Crowding Valuation: Evidence From College Students In Guangzhou, Jianrong Liu, Huiying Wen

Journal of Public Transportation

Overcrowding has grown to be an increasingly important issue for public transit in Guangzhou, China. To capture traveler benefits of reduced crowding from improved public transport, it is necessary to identify the relevant importance of crowding to travelers. This paper analyzes the disutility of crowding in metro car and bus transit with discrete choice models. Based on the stated preference survey data from college students in Guangzhou, the results show that there is non-negligible impact of crowding on passenger travel. The relationship between the disutility of crowding and standee density is not linear; that is, the disutility increases at a …

Effects Of Speed, Curves, And Driver Behavior On Passive Securement Systems On Large Transit Buses, Andrea Mather, Katharine Hunter-Zaworski

Journal of Public Transportation

Wheeled mobility devices that are not secured properly on large transit vehicles pose risks to all passengers. The purpose of this study was to increase the understanding of the effects of horizontal and vertical curves, speed, and driver behavior on the safety and security of people using wheeled mobility devices in rear-facing passive containment systems on large transit buses. Testing included the use of manual wheelchairs and lightweight scooters on an articulated low-floor transit bus. The project conclusions were derived from data produced by accelerometers placed on the bus as well as visual observations of wheeled mobility device movement. The …

Evaluation Of Horizontal Equity Under A Distance-Based Transit Fare Structure, Milad Bandegani, Meisam Akbarzadeh

Journal of Public Transportation

Horizontal equity requires equal distribution of investment/benefit/costs among equal members of society. In other words, a transit passenger should pay as much as he/she uses. This study evaluated the measure of fulfillment of this rule in a case study, developed a distance-based fare structure, and shows that justice is better served by switching to the proposed structure. Fare elasticity of demand and probability distribution of transit passenger trip lengths were investigated through a field survey. Although mainly used in the measurement of inequality in income or wealth, the Gini index and the recovery ratio (revenue to cost for each transit …

Pyrolysis Of Dried Wastewater Biosolids Can Be Energy Positive, Patrick J. Mcnamara, Jon Koch, Zhongzhe Liu, Daniel Zitomer

Civil and Environmental Engineering Faculty Research and Publications

Pyrolysis is a thermal process that converts biosolids into biochar (a soil amendment), py-oil and py-gas, which can be energy sources. The objectives of this research were to determine the product yield of dried biosolids during pyrolysis and the energy requirements of pyrolysis. Bench-scale experiments revealed that temperature increases up to 500 °C substantially decreased the fraction of biochar and increased the fraction of py-oil. Py-gas yield increased above 500 °C. The energy required for pyrolysis was approximately 5-fold less than the energy required to dry biosolids (depending on biosolids moisture content), indicating that, if a utility already uses energy …

Framework For Event-Based Semidistributed Modeling That Unifies The Scs-Cn Method, Vic, Pdm, And Topmodel, Mark Bartlett, Anthony J. Parolari, Jeffrey Mcdonnell, Amilcare Porporato

Civil and Environmental Engineering Faculty Research and Publications

Hydrologists and engineers may choose from a range of semidistributed rainfall-runoff models such as VIC, PDM, and TOPMODEL, all of which predict runoff from a distribution of watershed properties. However, these models are not easily compared to event-based data and are missing ready-to-use analytical expressions that are analogous to the SCS-CN method. The SCS-CN method is an event-based model that describes the runoff response with a rainfall-runoff curve that is a function of the cumulative storm rainfall and antecedent wetness condition. Here we develop an event-based probabilistic storage framework and distill semidistributed models into analytical, event-based expressions for describing the …

Minimum Conditions For Visible Mold Growth, G. A. Tsongas, Frank Riordan

Mechanical and Materials Engineering Faculty Publications and Presentations

Considerable confusion and misunderstanding exists over the conditions required for visible mold growth at a surface in buildings. That is evident in papers and articles authored by engineers and other scientists, including various ASHRAE, ASTM and Canada Mortgage Housing Corporation publications. One of the major problems is that many HVAC engineers, building scientists, practitioners and others believe there exists a single critical value of the relative humidity (RH) of the indoor or ambient air well away from surfaces, below which mold will not grow on surfaces. However, that is not the case. The purpose of this article is to clarify …

Tidal-Fluvial And Estuarine Processes In The Lower Columbia River: Ii. Water Level Models, Floodplain Wetland Inundation, And System Zones, David A. Jay, Amy B. Borde, Heida Diefenderfer

Civil and Environmental Engineering Faculty Publications and Presentations

Spatially varying water-level regimes are a factor controlling estuarine and tidal-fluvial wetland vegetation patterns. As described in Part I, water levels in the Lower Columbia River and estuary (LCRE) are influenced by tides, river flow, hydropower operations, and coastal processes. In Part II, regression models based on tidal theory are used to quantify the role of these processes in determining water levels in the mainstem river and floodplain wetlands, and to provide 21-year inundation hindcasts. Analyses are conducted at 19 LCRE mainstem channel stations and 23 tidally exposed floodplain wetland stations. Sum exceedance values (SEVs) are used to compare wetland …

Transportation System Vulnerability And Resilience To Extreme Weather Events And Other Natural Hazards: Report For Pilot Project — Kytc District 1, Benjamin L. Blandford, Scott Schurman, Candice Y. Wallace, Sarah M. Mccormack

Kentucky Transportation Center Research Report

This research’s objective is to assist the Kentucky Transportation Cabinet (KYTC) in its efforts to develop strategies to address natural hazard vulnerabilities and improve the resiliency of Kentucky’s transportation infrastructure. Recent federal legislation calls for state transportation agencies to develop a risk-based asset management plan for National Highway System (NHS) assets that includes consideration of natural hazards. Similarly, the Federal Highway Administration (FHWA) calls for state transportation agencies to identify potential vulnerabilities associated with extreme weather events and climate change, and to incorporate these findings into transportation planning, design, and maintenance practices.

Influent Wastewater Microbiota And Temperature Influence Anaerobic Membrane Bioreactor Microbial Community, Matthew Seib, K. J. Berg, Daniel Zitomer

Civil and Environmental Engineering Faculty Research and Publications

Sustainable municipal wastewater recovery scenarios highlight benefits of anaerobic membrane bioreactors (AnMBRs). However, influences of continuous seeding by influent wastewater and temperature on attached-growth AnMBRs are not well understood. In this study, four bench-scale AnMBR operated at 10 and 25 °C were fed synthetic (SPE) and then real (PE) primary effluent municipal wastewater. Illumina sequencing revealed different bacterial communities in each AnMBR in response to temperature and bioreactor configuration, whereas differences were not observed in archaeal communities. Activity assays revealed hydrogenotrophic methanogenesis was the dominant methanogenic pathway at 10 °C. The significant relative abundance of Methanosaeta at 10 °C concomitant …

The Feasibility Of Utilising Compressed Natural Gas As Part Of A Systematic Approach To Establishing The Necessary Groundwork For The Hydrogen Based Transport Economy, James Brunton, John Howlett, David Kennedy

Conference Papers

One key objective for vehicle manufacturers is to develop technology and infrastructure to facilitate the progression from combustion to conversion by the year 2050. In the short to medium term however, the combustion of fossil fuels such as petrol and diesel, coupled with advanced transmission innovations and emission control technology that are governed by strict Euro VI regulations appears to be the main path forward for the transport sector and the environment. This paper presents the feasibility of utilising the developing compressed natural gas network capabilities as part of a systematic approach to establishing the necessary groundwork for a hydrogen …

Post-Liquefaction Residual Strength Assessment Of The Las Palmas, Chile Tailings Failure, Tristan Reyes Gebhart

Master's Theses

Assessment of post-liquefaction residual strength is needed for the development of empirically-based, predictive correlations for earthquake engineering design. Previous practice commonly assigned negligible strengths to liquefied materials for engineering analysis, producing overly-conservative designs. Increasingly available case history data, and improved analytical tools have allowed for more accurate and less overly-conservative estimation of soil residual strength, improving empirical predictive models. This study provides a new case history to the limited suite of (approximately 30) liquefaction failure case histories available for post-liquefaction in-situ strength predictive correlations.

This case history documents the Las Palmas gold mine tailings dam failure, resulting from seismic-induced liquefaction …

Research On High-Rap Asphalt Mixtures With Rejuvenators And Wma Additives, Hamzeh Haghshenas, Hesanaddin Nabizadeh, Yong-Rak Kim, Kommidi Santosh

Nebraska Department of Transportation: Research Reports

No abstract provided.

Performance Of Advance Warning Systems In A Coordinated System, Li Zhao, Laurence R. Rilett, Ernest Tufuor, Waleed Khan, Christopher Lefrois

Nebraska Department of Transportation: Research Reports

The Advance Warning System (AWS), developed by the Nebraska Department of Roads (NDOR) has proven to be effective at improving traffic safety at isolated signalized intersections. However, the effectiveness of the system has not been analyzed at signalized intersections operating in a coordinated mode. This project analyzed AWS on arterials where the signals operate in a coordinated mode. The test bed consisted of nine sites, which are located at five successive coordinated signalized intersections on Highway 281 in Grand Island, Nebraska. A non-intrusive data collection system was used to collect a continuous traffic stream of data up to 1200 ft …

Wetlands And Coastal Systems: Protecting And Restoring Valuable Ecosystems, C. T. Agouridis, K. R. Douglas-Mankin, A. C. Linhoss, A. R. Mittelstet

Biological Systems Engineering: Papers and Publications

Wetlands and coastal systems are unique, highly productive, and often threatened landscapes that provide a host of services to both humans and the environment. This article introduces a five-article Wetlands and Coastal Systems Special Collection that evolved from a featured session at the 2015 ASABE Annual International Meeting in New Orleans, Louisiana. The Collection provides perspectives on tools and techniques for enhancing the protection and restoration of wetlands and coastal systems with emphasis on vegetation, hydrology, water quality, and planning. Topics span the Florida Everglades (two articles) and Virginia floodplain (one article) wetland systems and include remote sensing (one article) …

Analysis Of Farm Vehicle Crashes And Safety Belt Usage, Kenneth R. Agent, Eric R. Green, Michael A. Fields

Kentucky Transportation Center Research Report

The use of safety belts and child safety seats has been shown to be an effective means of reducing injuries to motor vehicle occupants involved in traffic crashes. There have been various methods used in efforts to increase safety belt and safety seat usage. Past efforts have included public information campaigns, local followed by statewide legislation, and enforcement of the legislation.

The objectives of the study were to collect data and review related Kentucky data to determine the following information:

• usage rate specifically for occupants of farm vehicles,
• the number of registered farm vehicles and their percentage of all registered …

Analysis Of Traffic Crash Data In Kentucky (2011-2015), Eric R. Green, Kenneth R. Agent, Jerry G. Pigman, Michael A. Fields

Kentucky Transportation Center Research Report

This report documents an analysis of traffic crash data in Kentucky for the years of 2011 through 2015. A primary objective of this study was to determine average crash statistics for Kentucky highways. Rates were calculated for various types of highways and for counties and cities. Difference criteria were used for exposure.

Optimization Of Headway, Stops, And Time Points Considering Stochastic Bus Arrivals, Liuhui Zhao

Dissertations

With the capability to transport a large number of passengers, public transit acts as an important role in congestion reduction and energy conservation. However, the quality of transit service, in terms of accessibility and reliability, significantly affects model choices of transit users. Unreliable service will cause extra wait time to passengers because of headway irregularity at stops, as well as extra recovery time built into schedule and additional cost to operators because of ineffective utilization of allocated resources.

This study aims to optimize service planning and improve reliability for a fixed bus route, yielding maximum operator’s profit. Three models are …

15-08 Community-Aware Charging Station Network Design For Electrified Vehicles In Urban Areas: Reducing Congestion, Emissions, Improving Accessibility, And Promoting Walking, Bicycling, And Use Of Public Transportation, Ratna Babu Chinnam, Alper E. Murat

Transportation Research Center Reports

A major challenge for achieving large-scale adoption of EVs is an accessible infrastructure for the communities. The societal benefits of large-scale adoption of EVs cannot be realized without adequate deployment of publicly accessible charging stations due to mutual dependence of EV sales and public infrastructure deployment. Such infrastructure deployment also presents a number of unique opportunities for promoting livability while helping to reduce the negative side-effects of transportation (e.g., congestion, emissions, and noise pollution). In this phase, we develop a modeling framework (MF) to consider various factors and their associated uncertainties for an optimal network design for electrified vehicles. The …

Economic Modelling Of The Management Of Dredged Marine Sediments, Joseph R. Harrington, Jimmy Murphy, Mary Coleman, Declan Jordan, Tristan Debuigne, Gabor Szacsuri

Publications

This paper presents and applies an economic model developed for the management of dredged marine sediments. The model predicts direct project costs and direct, indirect and induced economic impacts. The model is applied to analyse the economic aspect of the specific potential beneficial use of dredged sediment for land rec-lamation in an Irish context. The model results show the potential economic benefits to land reclamation of using dredged sediment including its value as a potential substitute for quarry based material and as an alternative to traditional offshore dredged sediment disposal, where appropriate. Analysis of other sediment management ap-proaches including wetland …