The Highway capacity manual (HCM) utilizes passenger car equivalency (PCE) factors to estimate the effect of heavy vehicles on traffic stream behavior under free-flow conditions. However, these factors have been (mistakenly) used by professionals to conduct analyses for all traffic conditions, i.e., free-flow as well as forced-flow conditions. Recent empirical evidence suggests that the PCE factors for free-flow conditions largely underestimate the effect of heavy vehicles after the onset of congestion. The current study aims at developing PCE factors for heavy vehicles on freeways and multilane highways during congestion. The study utilizes empirical data and microscopic traffic simulation to develop a set of PCE factors on level terrain and specific upgrades during congestion. The format of the proposed PCE factors is very similar to that of the HCM PCE factors for free-flow conditions. It is believed that the use of the proposed PCE factors for oversaturated conditions will help to largely improve the ...

Many construction-related training and education programs in the United States have now embraced the concept of sustainability, offering sustainable construction courses that highlight sustainable design and construction practices. These courses have mainly focused on green building strategies for the design and construction of built environments and indoor environmental quality necessary for students’ knowledge enhancement and career development. This study examined the effect of sustainability course on students’ knowledge as well as their perceptions of social responsibility and sustainable behaviors. Data were collected by conducting a survey from construction related programs in U.S. universities. Students were categorized based on their experience of taking such course(s), and results were compared in terms of their environmental concerns, objective and subjective knowledge, and sustainable consumer behaviors by conducting independent two-sample t-tests. The purpose of this study was to examine sustainable behaviors and social responsibility perceptions among U.S. university students enrolled in construction-related courses. The results indicated that environmental concern and sustainable consumer behavior scores were significantly lower among students who had taken the course than those who had not. Both objective and subjective knowledge scores were relatively low. There was no difference between the two groups in objective knowledge scores and unexpectedly, subjective knowledge was significantly lower among students who had taken the course than those who had not. The findings of this study provide implications for sustainability curriculum development that can enhance students’ learning experience.

This study explores new technologies for detecting structural failures in temporary structures by applying image processing techniques for the automated detection of structural failures. Temporary structures provide support for permanent structures during construction and serve as work platforms for construction workers, but most standards for temporary structures are voluntary. Design and construction considerations, therefore, are thus left to individual engineering judgement. The new approach utilizes a series of chronological digital images to detect incipient structural instability during the construction process. Any structural deformation becomes a measurable variable through image analysis and can serve as a measurable harbinger of structural failure. The proposed technology matches images in the series with their predecessors to highlight and locate differences in the structure. The small-scale experiment conducted and validated that the proposed methodology shows great potential for detecting micro changes that are too small to be detected by eye. The chronological images are expected to provide a coherent and persistent structural deficiency data-set that can be applied to diagnose physical forms of failure at an early stage of deformation, defining a clear starting point for rehabilitation and enabling structural engineers to draft and implement a comprehensive plan to address incipient problems in temporary structures.

Combined sewer overflow (CSO) is a significant environmental concern and public health risk (e.g., water contamination, eutrophication, and beach closure). The Environmental Protection Agency (EPA) has introduced the National Pollutant Discharge Elimination System (NPDES) permitting program to regulate and address this matter. This program mandates the control of CSOs for more than 700 municipalities obligated to devise Long-term Control Plans (LTCPs) to curb combined sewer overflows and reduce them to safe levels. The LTCP involves diverse strategies, including sewer separation, green infrastructure improvements, and conventional gray infrastructure upgrades. This study investigates several municipalities’ solutions for CSO problems that use conventional methods and wireless sensor technology as real-time control, mainly focusing on a comparative analysis of two cities, Richmond, Virginia, and South Bend, Indiana, such as their average rainfall, the frequency of overflows, and the capacity of treatment plants. The findings indicate that integrating sensor technology could significantly enhance modeling endeavors, bolster the capacity of existing structures, and substantially enhance preparedness for storm events. The EPA’s Storm Water Management Modeling (SWMM) software is utilized. Through an analysis of SWMM data, the study suggests the potential for leveraging wireless sensor technology to achieve more robust control over CSOs and significant cost savings as a part of LTCPs.

I.A.A.R.C. - International Association for Automation and Robotics in Construction Civil Engineering