Engineering Commons^™

The Potential For Real-Time Traffic Crash Prediction, Mohamed Abdel-Aty, Anurag Pande, Liang Y. Hsia, Fathy Abdalla

Civil and Environmental Engineering

The development of freeway crash prediction models using intelligent transportation systems (ITS) archived data could be a substantial advancement in the field of real-time traffic management. Such models not only are expected to improve safety but also may go a long way to improve freeway operations by reducing incident-related congestion.

Because there is a need to use real-time traffic data emanating from loop detectors, the approach differs distinctly from previous studies estimating crash frequencies or rates on a certain freeway section through aggregate measures of flow (such as average daily traffic or hourly volumes).

Although the authors try to establish …

Heat Generation In Municipal Solid Waste Landfills, Nazli Yesiller, James Hanson, Wei-Lien Liu

Civil and Environmental Engineering

This study was conducted to investigate thermal aspects of municipal solid waste landfills as a function of operational conditions and climatic region. Spatial and temporal distributions of waste temperatures were determined at four landfills located in North America (Michigan, New Mexico, Alaska, and British Columbia). Temperatures of wastes at shallow depths (extending to 6 to 8 m depth) and near the edges of a cell (within approximately 20 m) conformed to seasonal temperature variations, whereas steady elevated temperatures (23 to 57°C) with respect to air and ground temperatures were reached at depth and at central locations. Waste temperatures decreased from …

Role Of Higher-"Mode" Pushover Analyses In Seismic Analysis Of Buildings, Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

The role of higher-“mode” pushover analyses in seismic analysis of buildings is examined in this paper. It is demonstrated that the higher-“mode” pushover curves reveal plastic hinge mechanisms that are not detected by the first-“mode” or other FEMA-356 force distributions, but these purely local mechanisms are not likely to develop during realistic ground motions in an otherwise regular building without a soft and/or weak story. Furthermore, the conditions necessary for “reversal” of a higher-“mode” pushover curve are examined. It is shown that “reversal” in a higher-“mode” pushover curve occurs after formation of a mechanism if the resultant force above the …

Proactive Real-Time Traffic Safety Implementation Strategy On Freeways, Mohamed Abdel-Aty, Anurag Pande, Nizam Uddin

Civil and Environmental Engineering

Reactive traffic management strategies such as incident detection are becoming less relevant with the advancement of mobile phone usage. Freeway management in the 21^st century needs to shift focus toward proactive strategies that include anticipating incidents such as the crashes. Predicting crash occurrences would also be the key to traffic safety. A two-step approach to identify freeway locations with high probability of crashes through real-time traffic surveillance data is presented here. For this study historical crash and corresponding traffic data from loop detectors were gathered from a 58-km (36-mile) corridor of Interstate-4. Following an exploratory analysis two types of …

Cm Facilities Update, Construction Management Department

Construction Management

No abstract provided.

Traffic Surveillance From A Safety Perspective: An Its Data Application, M. Abdel-Aty, A. Pande, N. Uddin

Civil and Environmental Engineering

Reactive traffic management strategies such as incident detection are becoming less relevant with the advancement of mobile phone usage. Freeway management in the 21^st century needs to shift focus toward proactive strategies that include anticipating incidents such as the crashes. “Predicting” crash occurrences would also be the key to traffic safety. A two-step approach to identify freeway locations with high probability of crashes through real-time traffic surveillance data is presented here. For this study historical crash and corresponding traffic data from loop detectors were gathered from a 58-km (36-mile) corridor of Interstate-4. Following an exploratory analysis two types of …

Identification Of Rear-End Crash Patterns On Instrumented Freeways: A Data Mining Approach, A. Pande, M. Abdel-Aty

Civil and Environmental Engineering

Data mining is the analysis of large “observational” datasets to find unsuspected relationships that might be useful to the data owner. It typically involves analysis where objectives of the mining exercise have no bearing on the data collection strategy. Freeway traffic surveillance data collected through underground loop detectors is one such “observational” database maintained for various ITS (Intelligent Transportation Systems) applications such as travel time prediction etc. In this research data mining process is used to relate this surrogate measure of traffic conditions (data from freeway loop detectors) with occurrence of rear-end crashes on freeways. The results from this analysis …

Integrated Temperature And Gas Analysis At A Municipal Solid Waste Landfill, James L. Hanson, Nazli Yesiller, Laurel A. Kendall

Civil and Environmental Engineering

This study is conducted to investigate heat and gas production at a municipal solid waste landfill. Periodic temperature and gas measurements have been taken at approximately 140 locations within the waste mass, liner systems, and cover systems at a midwestern U.S.A. landfill since 1999. Increasing temperatures (1 to 15°C/a) were observed for newly placed wastes whereas steady elevated temperatures (50 to 60°C) were observed in older wastes. Liner temperatures increased at a rate of approximately 2 to 4°C/a and stable elevated temperatures in excess of 30°C were observed after 5.5 years and under 42 m of waste height. Anaerobic decomposition …

Evaluation Of Modal And Fema Pushover Procedures Using Strong-Motion Records Of Buildings, Rakesh K. Goel

Civil and Environmental Engineering

The objective of this investigation is to evaluate the FEMA-356 Nonlinear Static Procedure (NSP) and a recently developed Modal Pushover Analysis (MPA) procedure using recorded motions of four buildings that were damaged during the 1994 Northridge earthquake. For this purpose, displacements and drifts from the FEMA-356 NSP and the MPA procedures are compared with the values “derived” from the recorded motions. It is found that the FEMA-356 NSP typically underestimates the drifts in upper stories and overestimates them in lower stories when compared to the recorded motions. Among the four FEMA-356 distributions considered, the “Uniform” distribution led to the most …

Weathering Effects On Biodegradation And Toxicity Of Hydrocarbons In Groundwater, Marie G. Dreyer, Yarrow M. Nelson, Christopher L. Kitts

Civil and Environmental Engineering

This study examined the effect of weathering on hydrocarbon biodegradation and toxicity at a former oil field near Guadalupe, California. Soil and groundwater at this site contains residual diesel-range hydrocarbons formerly used to dilute the viscous crude oil to facilitate pumping (Lundegard and Garcia, 2001). Natural attenuation is being considered at this site as a means of remediating residual hydrocarbons in soil and groundwater. To provide the lines of evidence required for use of natural attenuation at this site, this research was undertaken to determine if the hydrocarbons continue to be biodegradable after extensive weathering in the field. Observed hydrocarbon …

Microbial Activity Of Soil Following Steam Treatment, Barbara Orchard, Yarrow M. Nelson, Lynne Maloney, Christopher L. Kitts, Paul Lundegard

Civil and Environmental Engineering

The effect of steam treatment on subsurface aerobic and anaerobic microbial communities was investigated using multiple microbial assays. Soil samples were gathered and analyzed prior to, one month after, and eight months after a five-month field pilot test of steam injection and extraction. Aerobic soil samples were analyzed by respirometry, plate counts, and direct microscopic counts. Anaerobic microbial activity was examined by monitoring methane generation in anaerobic microcosms with gas chromatography. Respirometry showed pre-steam CO₂ production was consistent with natural attenuation, post-steam (one month) CO₂ production was below detection, and post-steam (eight months) CO₂ production was about …

Biodegradation Of Weathered Hydrocarbons In Laboratory Microcosms And Soil Columns Simulating Natural Attenuation Field Conditions, C. Robin Cunningham, Yarrow M. Nelson, Paul Lundegard

Civil and Environmental Engineering

Abstract of paper presented at conference.

Improving Safety And Security By Developing A Traffic Accident Prevention System, Mohamed Abdel-Aty, Nizam Uddin, Anurag Pande

Civil and Environmental Engineering

This research aims at developing accident prediction models to improve freeway safety. Also by reducing incident related congestion on freeways, response and evacuation times would also be reduced in emergency situations. There are considerable amounts of data that are collected and stored for ITS applications. This data includes speed, volume and occupancy provided by loop detectors. Most of these variables are known to be related to accident occurrence and patterns. Previous work has shown the effect of speed variation and volume on traffic safety. In most of the previous work, average or historical speed and volume data have been used. …

Seismic Response Of Linear And Non-Linear Asymmetric Systems With Non-Linear Fluid Viscous Dampers, Rakesh K. Goel

Civil and Environmental Engineering

This investigation is concerned with the seismic response of one‐story, one‐way asymmetric linear and non‐linear systems with non‐linear fluid viscous dampers. The seismic responses are computed for a suite of 20 ground motions developed for the SAC studies and the median values examined. Reviewed first is the behaviour of single‐degree‐of‐freedom systems to harmonic and earthquake loading. The presented results for harmonic loading are used to explain a few peculiar trends—such as reduction in deformation and increase in damper force of short‐period systems with increasing damper non‐linearity—for earthquake loading. Subsequently, the seismic responses of linear and non‐linear asymmetric‐plan systems with non‐linear …

Determination Of Surface And Thickness Characteristics Of Textured Geomembranes Using Image Analysis, Nazli Yesiller, Arif Cekic

Civil and Environmental Engineering

Image analysis was used to determine surface topography and thickness of textured geomembranes. Images of cross sections (specimen length × thickness) of geomembranes were obtained at 50× magnification using a digital optical microscope. Thickness was determined as the distance between the top and bottom surfaces along an entire cross section. For surface analysis, profiles of top and bottom surfaces were extracted from the cross section images. Amplitude, spatial, hybrid, and functional texture parameters were determined. Tests were conducted on eleven samples of HDPE and LLDPE geomembranes manufactured by co-extrusion and embossing at varying thicknesses. The geomembranes were classified into three …

Sensitivity And Uncertainty Analysis Coupled With Automatic Calibration For A Distributed Watershed Model, Misgana K. Muleta, John W. Nicklow

Civil and Environmental Engineering

Distributed watershed models should pass through a careful calibration procedure before they are utilized as a decision making aid in the planning and management of water resources. Although manual approaches are still frequently used for calibration, they are tedious, time consuming, and require experienced personnel. This paper describes an automatic approach for calibrating daily streamflow and daily sediment concentration values estimated by the US Department of Agriculture’s distributed watershed simulation model, Soil and Water Assessment Tool (SWAT). The automatic calibration methodology applies a hierarchy of three techniques, namely screening, parameterization, and parameter sensitivity analysis, at the parameter identification stage of …

System Identification Of Base-Isolated Building Using Seismic Response Data, T. Furukawa, M. Ito, K. Izawa, Mohammad N. Noori

Office of the Dean (CENG) Scholarship

Due to the complex nature of the excitation, and the inherent dynamics characteristics of restoring force of the base isolation systems, the response of base-isolated structures subject to strong earthquakes often experiences excursion into the inelastic range. Therefore, in designing base-isolated structures, the nonlinear hysteretic restoring force model of the base isolation system is frequently used to predict structural response and to evaluate structural safety. In this paper, the prediction error method system identification technique is used in conjunction with nonlinear state-space models for identification of a base-isolated structure. Using a variety of nonlinear restoring force models and bidirectional recorded …

Retesting Of Liquefaction/Nonliquefaction Case Histories In The Imperial Valley, Robb E.S. Moss, Brian D. Collins, Daniel H. Whang

Civil and Environmental Engineering

This paper describes the retesting of liquefaction and nonliquefaction field case histories in the Imperial Valley using the electric cone penetration test (CPT). Subsurface testing of the River Park and Heber Road sites first occurred following the 1979 Imperial Valley earthquake (Bennett et al. 1981, Youd and Bennett 1983). These two sites are rich in information because they have experienced several earthquakes in recent history, have been subjected to moderate levels of strong ground shaking, the liquefiable layers have appreciable fines content, and the sites contain a number of high-quality non-liquefied data points. The recent liquefaction case history database for …

Response To B. Maison's Discussion Of "Evaluation Of Modal And Fema Pushover Analyses: Sac Buildings", Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

No abstract provided.

Extension Of Modal Pushover Analysis To Compute Member Forces, Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

This paper extends the modal pushover analysis (MPA) procedure for estimating seismic deformation demands for buildings to compute member forces. Seismic demands are computed for six buildings, each analyzed for 20 ground motions. A comparison of seismic demands computed by the MPA and nonlinear response history analysis (RHA) demonstrates that the MPA procedure provides good estimates of the member forces. The bias (or error) in forces is generally less than that noted in earlier investigations of story drifts and is comparable to the error in the standard response spectrum analysis (RSA) for elastic buildings. The four FEMA-356 force distributions, on …

Probabilistic Liquefaction Triggering Based On The Cone Penetration Test, Robb E.S. Moss, Raymond B. Seed, Robert E. Kayen, Jonathan P. Stewart, Kohji Tokimatsu

Civil and Environmental Engineering

Performance-based earthquake engineering requires a probabilistic treatment of potential failure modes in order to accurately quantify the overall stability of the system. This paper is a summary of the application portions of the probabilistic liquefaction triggering correlations proposed recently proposed by Moss and co-workers. To enable probabilistic treatment of liquefaction triggering, the variables comprising the seismic load and the liquefaction resistance were treated as inherently uncertain. Supporting data from an extensive Cone Penetration Test (CPT)-based liquefaction case history database were used to develop a probabilistic correlation. The methods used to measure the uncertainty of the load and resistance variables, how …

Thermal Analysis Of Gcls At A Municipal Solid Waste Landfill, James L. Hanson, Nazli Yesiller, G. E. Swarbrick

Civil and Environmental Engineering

This study was conducted to determine long-term thermal regime of landfill liner systems using a field temperature monitoring program and numerical analysis of heat transfer. Temperatures in liner systems that contain geosynthetic clay liners (GCLs) were monitored prior and subsequent to waste placement. Data were collected in three cells at a landfill in Midwestern USA for more than five years. The liner system in one of the cells was left exposed (not covered with waste) for a period exceeding one year subsequent to cell construction. The lowest and highest GCL temperatures were .1°C and 35°C, respectively and the localized temperature …

Governors Highway Safety Associations And Transportation Planning: Exploratory Factor Analysis And Structural Equation Modeling, Sudeshna Mitra, Simon Washington, Eric Dumbaugh, Micael D. Meyer

Civil and Environmental Engineering

The Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991 mandated the consideration of safety in the regional transportation planning process. As part of National Cooperative Highway Research Program Project 8-44, "Incorporating Safety into the Transportation Planning Process," we conducted a telephone survey to assess safety-related activities and expertise at Governors Highway Safety Associations (GHSAs), and GHSA relationships with metropolitan planning organizations (MPOs) and state departments of transportation (DOTs). The survey results were combined with statewide crash data to enable exploratory modeling of the relationship between GHSA policies and programs and statewide safety. The modeling objective was to illuminate current hurdles …

Characterization Of Surface Topography Of Sand, Nazli Yesiller, James L. Hanson, Donald K. Cohen

Civil and Environmental Engineering

This study was conducted to investigate surface characteristics of sand particles. Surface topography of sand particles was determined in 3-D using a commercially available optical profiler. Measurements were made on areas that had side dimensions on the order of 0.1 mm at a lateral resolution of 0.3 μm and height resolution of less than 6 nm. The 3-D representation of a surface obtained using the measurement system is analyzed to determine 3-D as well as 2-D surface texture parameters. The parameters included amplitude, spacing, hybrid (amplitude and spacing), and functional (performance related) parameters. Tests were conducted on two silica sands: …

Thermal Analysis Of Gcls At A Municipal Solid Waste Landfill, J. L. Hanson, Nazli Yesiller, G. E. Swarbrick

Civil and Environmental Engineering

This study was conducted to determine long-term thermal regime of landfill liner systems using a field temperature monitoring program and numerical analysis of heat transfer. Temperatures in liner systems that contain geosynthetic clay liners (GCLs) were monitored prior and subsequent to waste placement. Data were collected in three cells at a landfill in Midwestern USA for more than five years. The liner system in one of the cells was left exposed (not covered with waste) for a period exceeding one year subsequent to cell construction. The lowest and highest GCL temperatures were –1°C and 35°C, respectively and the localized temperature …

Core Thickness And Asperity Height Of Textured Geomembranes: A Critical Review, Nazli Yesiller

Civil and Environmental Engineering

No abstract provided.

A Freeway Safety Strategy For Advanced Proactive Traffic Management, Anurag Pande, Mohamed Abdel-Aty

Civil and Environmental Engineering

Reactive traffic management strategies such as incident detection are becoming less relevant with the advancement of mobile phone usage. Freeway management in the 21st century needs to shift focus toward proactive strategies that include anticipating incidents such as crashes. A simple approach to identify freeway locations with high probability of crashes through real-time traffic surveillance data is presented here. The crash and loop detector data for the study was collected from 36-mile corridor of Interstate-4 in Orlando, Florida. The analysis is based on simple (one covariate) logistic regression models developed under a matched study design. Individual traffic parameters obtained one …

Identifying Crash Propensity Using Specific Traffic Speed Conditions, Mohamed Abdel-Aty, Anurag Pande

Civil and Environmental Engineering

Introduction: In spite of recent advances in traffic surveillance technology and ever-growing concern over traffic safety, there have been very few research efforts establishing links between real-time traffic flow parameters and crash occurrence. This study aims at identifying patterns in the freeway loop detector data that potentially precede traffic crashes.

Method: The proposed solution essentially involves classification of traffic speed patterns emerging from the loop detector data. Historical crash and loop detector data from the Interstate-4 corridor in the Orlando metropolitan area were used for this study. Traffic speed data from sensors embedded in the pavement (i.e., loop …

Spatiotemporal Variation Of Risk Preceding Crashes On Freeways, Anurag Pande, Mohamed Abdel-Aty, Liang Hsia

Civil and Environmental Engineering

Research into the application of freeway loop detector data for traffic safety has gained momentum in recent years. The incompleteness of data from loop detectors has been a common problem in both the development and the implementation of models. The effect of individual crash precursors, obtained one at a time from a series of loop detectors, on relative risk of crash occurrence was examined through within-stratum one-covariate logistic regression models. The hazard ratio (resultant change in log odds of observing a crash by changing the covariate by one unit) was used as the measure of risk. The log of coefficient …

Split Models For Predicting Multivehicle Crashes During High-Speed And Low-Speed Operating Conditions On Freeways, Mohamed Abdel-Aty, Nizam Uddin, Anurag Pande

Civil and Environmental Engineering

The future of traffic management and highway safety lies in proactive traffic management systems. Crash prediction models that use real-time traffic flow variables measured through a series of loop detectors are the most important component of such systems. A previous crash prediction model was developed with the matched case-control logistic regression technique. Although the model achieved reasonable classification accuracy, it remained open to improvement because of the limited study area, sample size, and transferability issues. Therefore, the previous work had been extended. Multivehicle freeway crashes under high- and low-speed traffic conditions were found to differ in severity and in their …