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The construction industry relies on construction cost indexes to prepare cost estimate benchmarks and develop cost estimates. Subsequently, government agencies, non-profit organizations, and private companies routinely publish construction cost indexes for cities. Currently, all construction cost indexes are released in a tabular format for 649 cities across the conterminous United States, which is not effective in illustrating construction cost variations at the national level. This study explored the utility of various established interpolation methods and mapping techniques to visualize construction cost indexes at the national level. Geovisualization techniques such as thematic mapping provide a visual representation of construction cost data in addition to traditional tabular formats. This study explored the utility of Thiessen polygon and inverse distance weighted (IDW) methods to create thematic maps which can be used to interactively visualize construction costs at the national level. A qualitative comparison revealed that the IDW method can produce the most intuitive, interactive, and continuous surface maps to identify dynamic and previously unrecognized patterns. These continuous surface maps allow construction practitioners and academics, real estate developers, and the public to locate the geographic proximity of high or low construction costs while cost change maps allow investors and businesses to identify patterns in changing construction costs over a certain period. This work contributes to the body of knowledge by introducing interpolated maps for visualizing any construction cost-related indexes at a large scale such as the national level.

The construction industry has extensively applied the fast-tracking approach to the demanding need for the fast delivery of infrastructure projects. However, the fast-track strategy might be threatened by distinctive risks or changes in risk characteristics that emerge when activities are overlapped (overlapping risks). This article proposes a risk assessment simulation model to quantify the economic impact of overlapping risks on fast-track infrastructure projects. The model uses Monte Carlo simulation and a proprietary engine solution for the optimization procedure. It quantifies the overlapping risk impacts in the project duration and cost that could originate in three different overlapping degrees and evaluates the optimal overlapping degree to reduce the impact of the overlapping risks. The model demonstration used a commercial renovation project. The results suggest that overlapping risks have a high potential impact on the total cost, although with a high probability of attaining the target duration. Eight top risks affected the total duration, cost, or both. The optimum overlapping to reduce the economic impact and achieve the target project duration combines different overlapping degrees. This study contribution is a model for fast-track projects considering overlapping risks, their impact characteristic as a distribution, and the potential relationship between these risks.

Highway project delivery is a disruption-prone process in which resilience is essential to project success, because different project stages experience disruptions and struggle to reach des...

Ensuring the resiliency of a nation’s transportation infrastructure network requires a skilled and dependable workforce; this relies heavily on a transportation agency’s ability to recruit ...

Commercial and residential buildings consume about 27% of total energy used in the US, out of which nearly half is consumed by commercial building sector and it expected to grow in the next 30-year period. Literature suggests that occupancy data may improve the energy consumption of the buildings, especially in HVAC operation. In the past few years studies came up with various frameworks based on existing infrastructure to estimate occupancy, out of which commodity WiFi gained popularity in detecting, estimating, and tracking occupants within buildings. However, there are concerns with those frameworks such as added infrastructure and computational efforts, upgrades to existing infrastructure, and privacy of occupants. This paper presents a simplistic framework based on commodity WiFi to estimate real time occupancy data without any added infrastructure or upgrades, while protecting the occupant privacy and can produce significant energy reduction in HVAC operation. The framework is tested on a large lecture hall in an institutional building that has multiple classes scheduled. The initial tests showed that the WiFi based occupancy had a 0.96 correlation with the established ground truth. Additionally, the WiFi based occupancy schedule resulted in at least 50% savings in HVAC energy consumption over static schedule.

Project delivery is often subject to uncertainties and disruptions throughout the entire process. The ability of project delivery to resist and recover from disruptions is a measure of the ...

All transportation management agencies face the yearly challenge of inspecting the condition of myriad miles of road surface. With routinely acquired and publicly available geospatial data and geospatial modelling techniques, there is potential to substantially reduce the number of survey sites required to characterize overall pavement surface distress condition. Using roadway pavement assets in the State of New Mexico as an example, this study investigated if overall pavement surface conditions could be estimated based on geospatial modelling. A total of 17 explanatory variables, which were extracted from three types of geospatial data, including traffic volumes, environmental conditions and topography, were used to estimate overall pavement surface distress conditions. Results show that overall pavement surface conditions can be effectively (R2 > 0.9) estimated based on the extent of geospatial data and inferential modelling techniques with fewer survey sites, substantially reducing the cost and...

Building energy retrofits aim to reduce the energy consumption of existing facilities. The most significant impact of any energy retrofit project is during the operation phase of a building...

Sinkholes cause subsidence and collapse problems for many transportation infrastructure assets. Subsequently, transportation infrastructure management agencies dedicate a considerable amount of time and money to detect and map sinkholes as part of their asset management programs. Traditionally, sinkholes are detected through area reconnaissance, which includes visual inspection of a site to locate existing sinkholes or device inspection of a site to locate potential sinkholes or previously filled sinkholes. Another method for sinkhole detection is through a review of maps such as geological maps. These methods are expensive, time-consuming, and labor-intensive. Recent advances in remote sensing, especially airborne light detection and ranging (LiDAR), allows for the examination of the change in the Earth's surface elevation accurately and rapidly. The focus of this study is to develop a conceptual framework for sinkhole detection and mapping with airborne LiDAR. This conceptual framework lays the foundation for the future application of airborne LiDAR for sinkhole detection and mapping.

The objective of this study was to evaluate the construction, material characterization, initial structural assessment, and cost of a novel jointless Engineered Cementitious Composite Ultra-Thin Whitetopping (ECC-UTW) overlay. After construction, early-age cracks (from less than 0.25 mm to up to 2.54 mm width) were observed in the 101.6-mm (4 in.) jointless ECC-UTW section; yet, the majority of the cracks coincided with areas where fiber clumps were observed during construction and places of heavy instrumentation. On the other hand, no cracks were observed in the 63.5-mm (2.5 in.) jointless ECC-UTW at early ages; yet, when winter arrived, micro-cracks (

In recent years, unmanned airborne systems (UAS) have emerged as an important platform for collecting hyper-spatial resolution airborne remote sensing data. Using this hyper-spatial resolution imagery as input, modern aerial triangulation (AT) techniques, also known as structure-from-motion or SfM, can rapidly produce orthophotos and digital surface models (DSMs) at fine scales. Such data hold great promise for a number of applications, including routine and post-disaster assessment of transportation infrastructure, which provided the impetus for this research. Using hyper-spatial resolution (0.002 m) natural colour digital aerial photography acquired from a low-altitude UAS as input images, this research systematically investigated the horizontal and vertical accuracy of the AT generated orthophotos and DSMs, respectively. Hyper-spatial resolution aerial data were collected for a total of 28 study sites and, for each study site, coordinate information of 16 ground control points (GCPs) was collec...

State transportation agencies regularly collect data on pavement surface distresses. These data are used to assess overall pavement conditions and to make maintenance and repair decisions. Routinely-acquired and publically-available high spatial resolution (hsr) multispectral digital aerial photography provides a potential method for collecting distress information that can supplement or replace currently-used technologies. Principal component analysis and linear least squares regression models were used to evaluate the potential of using HSR multispectral digital aerial photographs to estimate pavement surface overall distress conditions. Various models were developed using HSR multispectral digital aerial photographs of different spatial resolution (6-inch, 12-inch, and 24-inch) and reference pavement surface distress data collected manually at multiple sample sites using standard protocols. The results show that the spectral response of HSR multispectral digital aerial photographs correlate strongly with reference distress rates at all tested spatial resolutions, but the 6-inch aerial photos exhibit the strongest correlation (R 2 > 0.95), even when using only half of the sample sites (R 2 > 0.92). These results indicate that straightforward analysis of HSR multispectral digital aerial photographs, routinely acquired by most municipalities and states, can permit assessment of pavement surface distress conditions as well as current manual evaluation protocols.

Increasing the use of social sustainability in the decision-making process for building and infrastructure projects requires that it be defined such that it can be evaluated objectively. One potential indicator of social sustainability in infrastructure projects is public opinion, which can provide a means to evaluate the level of social sustainability on a project based on personal values. Public opinion includes both support and opposition for a project. In this study, the causes or triggers for public opposition to a construction project are identified and then compared to principles of social sustainability to determine if they are related. Eight case study projects were used to identify common triggers of public opposition. The results suggest that common triggers of public opposition are related to land acquisition, escalating construction costs and the presence of endangered species on the project site. Eight of the twelve principles of social sustainability that were identified were determined to be related to public opposition. The results of this study suggest that public opposition could be used as a measure for some elements of social sustainability but that further research into other measures for social sustainability is necessary.

A fundamental process in construction cost estimation is the appropriate adjustment of costs to reflect project location. Unfortunately, location adjustment factors are not available for all locations. To overcome this lack of data, cost estimators in the United States often use adjustment factors from adjacent locations, referred to as the nearest neighbor (NN) method. However, these adjacent locations may not have similar economic conditions, which limit the accuracy of the NN method. This research proposes a new method of using nighttime light satellite imagery (NLSI) to estimate location adjustment factors where they do not exist. The NLSI method for estimating location adjustment factors was evaluated against an established cost index database, and results show that NLSI can be used to effectively estimate location adjustment factors. When compared with NN and other alternative proximity-based location adjustment methods, the proposed NLSI method leads to a 25–40% reduction of the median abso...

Roadway networks, as part of transportation infrastructure, play an indispensable role in regional economies and community development. The high-quality pavement serviceability of these networks is essential to ensure safe, cost-effective daily traffic operations. In-depth analyses of network-wide pavement surface condition data are necessary inputs for optimal pavement design and maintenance, traffic safety enhancement, and sustainable traffic infrastructure system development. This study aims to investigate various pavement distress condition performance measurements and their correlations to better understand temporal–spatial characteristics of roadway distress based on pavement distress condition data collected in New Mexico from 2006 to 2009. Eight major corridors across various urban and rural areas were selected for analyzing pavement surface-distress conditions and discovering their intrinsic characteristics and patterns across both temporal and spatial domains. The results show that there are not strong correlations among different distress measurements, implying the rationality of the current pavement performance measurement protocol used by the state transportation agencies. Regression models were established and GIS-based spatial analyses were performed to extract temporal and spatial patterns of Distress Rate (DR) data. The model results illustrate significant correlations of the DR data on the same route between two consecutive years, which can be partially characterized by a Markov process. GIS-based spatial investigations also show unique features of pavement condition deterioration attributed to diverse geometric characteristics and traffic conditions, such as vehicle compositions and volumes and urban and rural areas. The research findings are helpful to understand the characteristics of pavement distress conditions more clearly and to optimize traffic infrastructure design and maintenance.

The monitoring of construction workforce physical strain can be a valuable management strategy in improving workforce productivity, safety, health, and quality of work. Nevertheless, clear relationships between workforce performance and physical strain have yet to be established. An exploratory investigation of the relationship between task level productivity and physical strain was conducted. Nine participants individually performed a four-hour simulated construction task while a wearable physiological status monitor continuously assessed their physiological condition. Heart rate, relative heart rate, and breathing rate were utilized as predictors of physical strain, and task level–single factor productivity was used as an index of productivity. Numerous regression models were generated using the collected data. This investigation initially unsuccessfully attempted to establish a relationship between physiological condition and productivity at the individual worker level. However, an analysis of the regr...

Previous studies on building, industrial, and transportation projects found that projects delivered using design-build tend to perform better than projects delivered with the traditional de...

Sustainability is often described in terms of the triple bottom line, which refers to its environmental, economic, and social dimensions. However, the economic and environmental impacts of decisions have been easier to determine than have been the social impacts. One area of social sustainability that is particularly applicable to construction projects is that of construction workforce safety and well-being. This is a critical part of sustainability, and a socially sustainable construction industry needs to consider the safety and well-being of construction workers. However, construction activities are generally physically demanding and performed in harsh environments. Monitoring workers’ physical strain may be an important step toward enhancing the social sustainability of construction. Recently introduced physiological status monitors (PSMs) have overcome the past limitations, allowing physical strain to be monitored without hindering workers’ activities. Three commercially available PSMs have b...

Owners of water/wastewater facilities can choose from several project delivery methods, including the traditional design-bid-build method or an alternative design-build method. When choosing a project delivery method, the owner should consider both the project goals as well as the performance of different project delivery methods. Detailed data on project delivery performance allow owners to match project goals, such as time savings, with project delivery methods. Detailed data on project delivery performance do not currently exist for the water/wastewater sector. Through a survey of water/wastewater facility owners, data were collected on 31 design-build projects and sixty-nine design-bid-build projects. A statistical analysis of the data determined that schedule growth for design-build projects was half that of design-bid-build projects; more design-build projects finished at or below budget; and both project delivery methods produced projects of comparable quality. Although this is the first st...

Roadway pavement surface distress information is critical for effective pavement asset management, and subsequently, transportation management agencies at all levels (i.e., federal, state, and local) dedicate a large amount of time and money to routinely evaluate pavement surface distress conditions as the core of their asset management programs. However, currently adopted ground-based evaluation methods for pavement surface conditions have many disadvantages, like being time-consuming and expensive. Aircraft-based evaluation methods, although getting more attention, have not been used for any operational evaluation programs yet because the acquired images lack the spatial resolution to resolve finer scale pavement surface distresses. Hyper-spatial resolution natural color aerial photography (HSR-AP) provides a potential method for collecting pavement surface distress information that can supplement or substitute for currently adopted evaluation methods. Using roadway pavement sections located in the State of New Mexico as an example, this research explored the utility of aerial triangulation (AT) technique and HSR-AP acquired from a low-altitude and low-cost small-unmanned aircraft system (S-UAS), in this case a tethered helium weather balloon, to permit characterization of detailed pavement surface distress conditions. The Wilcoxon Signed Rank test, Mann-Whitney U test, and visual comparison were used to compare detailed pavement surface distress rates measured from HSR-AP derived products (orthophotos and digital surface models generated from AT) with reference distress rates manually collected on the ground using standard protocols. The results reveal that S-UAS based hyper-spatial resolution imaging and AT techniques can provide detailed and reliable primary observations suitable for characterizing detailed pavement surface distress conditions comparable to the ground-based manual measurement, which lays the foundation for the future application of HSR-AP for automated detection and assessment of detailed pavement surface distress conditions.

Concurrent engineering is the process of reducing the total project delivery time by overlapping activities that normally occur sequentially. The benefits are a shortening of delivery time and a possible reduction in overall costs. However, there are potential risks to overlapping dependent activities. The interaction between an upstream activity and a downstream activity relies on how information evolves in the upstream activity and how sensitive the downstream activity is to that changing information. This implies that if an upstream activity is slow to evolve information and a downstream activity is highly sensitive to changing information, the risk in overlapping these activities will be higher than activities that are fast to evolve and not as sensitive to changing information. The risk can manifest in rework, or reperforming some aspect of the downstream activity because of the evolution of the upstream activity and the amount of overlapping used. This research developed computer simulation models to better understand the potential risk of rework. The simulation models allow for overlapping different types of slow- and fast-evolving upstream activities with high- and low-sensitivity downstream activities using overdesign and early release strategies and different amounts of overlapping. The overall findings show that simulations of overlapping activities yield a reliable approach to modeling concurrent engineering activities. The simulations provide information on the probability of rework based on the different combinations of evolution, sensitivity, overlapping strategy, and the percent amount of overlapping used between the upstream and downstream activity. The use of computer simulations and modeling of overlapping activities therefore allows engineers and managers to understand the potential risks and what strategies to apply when utilizing concurrent engineering on a project.

The process by which a building owner evaluates and decides upon energy conservation measures (ECMs) for a building retrofit is key towards achieving efficient results. However, many owners rely on unsophisticated evaluation methods, which potentially limits the amount of energy reduced in the commercial building. Reducing energy in the nearly 4.9 million commercial buildings is critical because they account for approximately one fifth of the total energy consumption in the United States. Reducing their energy consumption levels will have significant impacts on energy dependency, Greenhouse Gas emissions (GHG), and operations costs. The decision processes of twelve private and public organizations in New Mexico were evaluated through collective case study research. The processes of each organization were compared and key steps were identified. Then the most used and critical steps were combined to create an integrated decision approach that optimizes cost savings and GHG emission reductions. This integrated decision process involves five main steps: (1) Building Energy Data; (2) Energy Identification and Analysis; (3) Assessment; (4) Design and Planning; and (5) Approval.

In a continued effort to provide water and wastewater facilities, owners have been using a variety of contract pricing methods for the construction of new facilities. Increasing use of cost-plus-fee with a guaranteed maximum price (GMP) contract payment provisions along with the more traditional lump sum contract payment provisions has created a need to measure the effectiveness of these contract pricing methods. Through a detailed survey of public water and wastewater facility owners, performance data were collected to compare project performance based on schedule and cost growth measures. The results of this study indicate that contracts using cost-plus-fee with a GMP contract pricing provisions are more likely to have no schedule or cost growth as compared to projects with lump-sum provisions. Overall, the results of this study provide new data for water and wastewater projects that can be used by owners to improve future project performance.

Evaluations of surface distresses in pavements, such as cracking, bleeding, and raveling, are often used as one component of overall pavement condition indexes. Both manual and automated survey methods are available for pavement distress evaluation; however, all distress evaluations experience a certain level of variability in their results. How this level of variability is determined depends on the type of data collected during the pavement distress evaluations. When distress data are collected as ordinal values, the variability may be determined by comparison of pairs of ranked values. This paper presents one rank correlation method, Kendall's correlation coefficient, and illustrates how it can be used to assess variability in ordinal distress data collected through manual surveys. Using Kendall's correlation coefficient, variability between different raters and variability between multiple evaluations by one rater were determined for each individual distress type. As a result, the ratings for certain distresses such as bleeding were found to have a high level of variability. This information can be useful when used to develop training programs to reduce data variability.

Transportation agencies are increasingly interested in new strategies for integrated project delivery, such as design–build. When making a decision between a traditional design–bid–build delivery and an integrated project delivery such as design–build, the agency should consider potential cost savings, time savings, and quality improvements. To maximize the success of design–build projects, transportation agencies need to pay attention to several aspects of this system, including initial steps like contract procurement. Agencies should prepare for the procurement phase carefully on the basis of project size, complexity, timing, selection methods, and so on. This is especially important for design–build projects in which participating firms invest significant effort during the contract procurement phase while planning design and construction and assessing risks. To assist in improving the success of design–build projects, a study was conducted to analyze the relationship between duration of the contract procurement phase and project performance. Schedule growth, cost growth, and total project time growth were used to measure project performance in the study. Linear regression analysis was used to analyze the relationship between procurement duration and each of the three project performance factors. The results show a strong linear correlation between procurement duration and schedule growth. Longer procurement duration correlates less with schedule growth as a percentage of the total project schedule. There is no evidence to indicate that longer procurement duration will reduce cost growth. This research strongly suggests that providing additional time to contractors during procurement allows them to improve schedule performance.