This study empirically examines the performance of alternative contracting methods using data from 2,721 highway projects gathered from a Florida Department of Transportation database. Contracting ...methods can significantly influence the cost and time of highway projects, so it is essential to use appropriate contracting methods in highway projects, especially considering the huge current volume of work and great need for more lane miles and new bridges. The most widely used alternative contracting methods in horizontal construction include Design–Build Major, Design–Build Minor, Cost Plus Time, Incentive/Disincentive, Lump Sum, and No Excuse Bonus. These have been devised to overcome shortcomings of the conventional Design–Bid–Build (DBB) method; however, their actual performance in practice has not previously been rigorously studied. To fill this gap, we statistically analyze our sample of highway projects using the Shapiro–Wilk test, Levene’s test, Kruskal–Wallis test, Wilcoxon–Mann–Whitney test, and Dunn’s test for unequal sample sizes. Another unique contribution of this research is the analytical techniques employed, which led to more reliable results based on the large quantity of data gathered. We find that some contracting methods performed better than others in each cost category for cost and time, and based on average cost and time savings, but not all were confirmed statistically. All seven contracting methods performed better in achieving time reductions than cost reductions, and all methods were more effective in reducing the cost and time of projects worth less $20 million than those worth over $20 million.
This study aims to assess various perceived adverse effects of noise on construction sites according to the different stages and machinery used in the stages, and to examine whether or not ...personal-situational factors affect the judgment of managers regarding the adverse impact of noise at work through a self-reported survey method. Four primary construction stages and twenty-four types of construction machines were evaluated. The effects of personal (noise sensitivity) and situational (types of jobs, and years of working) factors on the adverse impacts of noise on annoyance, work performance, work safety, and speech interference at work were examined. The results show significant differences in perceived noise annoyance in the various construction stages. The demolition stage is the most annoying, followed by the foundation, earthwork, and concrete framing stages. In addition, the annoying equipment differs for each construction stage. A breaker, pile driver, and hammer compactor are rated as the most annoying construction machines in the demolition, foundation, and earthwork stages, respectively. Individual noise sensitivity appears to have the most significant influence on the adverse impacts of noise on annoyance, work performance, work safety, and speech interference. A high noise sensitivity group tends to judge construction noise to be more adverse than the rest. In addition, different interrelationships between the adverse items of noise are found across their types of jobs: building construction, civil construction, and safety management. The findings of this study will provide further knowledge to facilitate better noise management planning on construction sites.
•Demolition stage is the most annoying stage on construction sites.•Machines that emits high noise level with high temporal variation are more annoying.•Noise sensitivity appears to have the most significant influence on the adverse impacts.•Significantly different correlations between the adverse impacts of noise are found across job types.
State Transportation Agencies (STAs) recognized that to enhance the quality of construction documents, a review process must be incorporated into project planning, design, and procurement to evaluate ...projects for constructability. The benefits promised by constructability reviews (CRs) encouraged STAs to adopt it as part of their operations. This approach soon evolved into a structured process, recognized by researchers and practitioners as, the constructability review process (CRP). A significant component to the CRP success is to involve experienced construction personnel in CRs during the design phase; a major limitation of the traditional design-bid-build (DBB) delivery method. To overcome this limitation, more emphasis is being placed towards alternative project delivery methods (APDMs). As such, design–build (DB) and construction manager/general contractor (CM/GC) are among the APDMs most utilized by STAs to deliver transportation projects. Although extensive research has investigated CRs under DBB projects, research on CRs implementation under APDMs is remarkably absent. This study examines CRs utilization and staffing practices adopted by STAs across DBB, DB, and CM/GC projects. The results of this study were drawn utilizing data collected through a national survey questionnaire and interviews with selected STAs. The study found that CRs are initiated and implemented at proportionally similar phases across DBB, DB, and CM/GC projects. Investigation of staffing needs revealed that although the agency holds the executive role in implementation of CRs on DBB projects, their role shifts on DB projects to become more administrative. The agency continues to be involved in CRs under CM/GC projects, along with their allocated design consultant, in conjunction with the GC. The results of this study are anticipated to provide STAs with guidance for CRs utilization on DBB, DB and CM/GC projects.
AbstractThis paper presents the results of a study to compare the performance of design-bid-build (DBB), construction manager at risk (CMR), and design-build (DB) project delivery systems in the US ...building construction industry. By leveraging verified data from 212 projects, a best subset analysis was used to generate regression models that explain the greatest amount of variance in five measures of project performance: unit cost, cost growth, schedule growth, construction speed, and delivery speed. From these regression models, the average of the predicted project performance was calculated for each delivery system when holding all other variables constant. The results show that, on average, projects with a DB delivery system are delivered faster and with lower cost and schedule growth than projects structured as CMR or DBB. In addition, the completed unit cost of DB projects is comparable to DBB and slightly less than CMR projects. These results are generally consistent with findings from seminal articles published in the late 1990s, as well as more recent works that also compared performance across delivery systems. However, the modeling does indicate that, except for delivery speed, the gap in performance between DBB, CMR, and DB has narrowed over time. This research provides an updated benchmark for the performance of the most commonly used project delivery systems, which has value to owners seeking guidance when making strategic decisions in structuring their projects.
•How construction managers decide safety measures for older workers was studied.•Factors examined covered dimensions of workers, managers, and safety measures.•The perceptions and demographics of ...managers play critical roles in this decision.•Workers of senior skill or accident records are likely to obtain safety measures.
Construction managers play critical roles in facilitating the retention and safety of an ageing workforce. This study aims to examine the factors underlying the high behavioural intention of construction managers to implement safety measures for their older workers. A vignette study was conducted amongst 161 construction managers in Hong Kong. The factors examined covered the dimensions of the characteristics of older construction workers, types of safety measures, and the perceptions and demographics of construction managers. The results revealed that participants most frequently (46%) treat those aged 60 years and over as older construction workers. The perceptions in awareness of workforce ageing (p < 0.01), age norms (p < 0.01), and attitude towards older workers (p < 0.01) of the participants play critical roles in influencing their likelihood of possessing high behavioural intention to implement safety measures. Participants who work in small (OR = 1.659, p < 0.05) or very large companies (OR = 1.965, p < 0.01) or have limited work experience (the OR of work experience is 0.981, p < 0.05) tend to have high behavioural intention of implementing safety measures. In addition, the participants are less likely to implement safety measures for semi-skilled workers (OR = 0.793, p < 0.05) but more likely for those who have a history of accidents (OR = 1.319, p < 0.05). The findings of this study provide a conceptual framework associated with the influential factors that predict the motivation of construction management in enhancing the occupational safety of older workers.
AbstractThe construction of public schools is a complex endeavor due to the involvement of multiple and diverse parties, funding and budgetary concerns, and statutory limitations imposed by local, ...state, and federal agencies, all of which serve to increase project risk. Project delivery methods using distinctive procedures to manage the design and construction process have been developed to reduce risk and improve project performance. To increase the probability of successful project outcomes, those responsible for public school construction require conclusive delivery method performance data. Completed in 2014, this two-year study used actual construction documents from 137 southeastern public schools to analyze and determine project delivery method cost, time, quality, and claims performance. The analysis indicated that performance of the Design-Bid-Build (DBB) method was significantly superior across all cost metrics, whereas the Construction Manager at Risk (CM at Risk) method produced higher levels of product and service quality. Essentially, public school administrators were paying a significant premium to obtain perceived improvements in both service and product quality. This research empowers decision-makers and benefits the public by providing evidence of the most efficient and effective means for the construction of new public schools.
The aim and purpose of the research are to analyze the performance of the technical supervision of the investor within the Czech construction industry during the construction, particularly focused on ...transport line structures. It is about clarifying the meaning and role of technical supervision in the public sector in transportation structures. In the first phase, a literature search is carried out on the current state of performance of the technical survey, and its work content is determined, including the method of its evaluation within the framework of a public contract. On the basis of these conclusions, a questionnaire is designed, which determines the real time-consuming activities during the performance of supervision and, at the same time, examines the tools used in its performance. Conclusions from the questionnaire research are examined, and steps for possible streamlining are proposed. As part of the examination of the proper evaluation of performance, a more suitable model of evaluation of these services is sought based on the previous analysis of the time-consuming nature of the technical supervision activity and according to the existing evaluation methods. Doi: 10.28991/CEJ-2023-09-03-013 Full Text: PDF
PurposeThe purpose of this study is to determine the barriers and constraints executive decision-makers have to face during the delivery method selection stage of water and wastewater projects using ...alternative project delivery (APD) methods, e.g. design-build (DB), design-build-operate (DBO) and construction management-at-risk (CMAR).Design/methodology/approachStructured interviews were conducted with 18 executive decision-makers from public agencies to identify the reasons for transitioning to APD from the design-bid-build (DBB) method. Respondents were also asked about the major obstacles they faced during the decision-making process, as well as key positive and negative factors in using APD methods. The executive decision-makers were also asked about their lessons learned during this process. In addition, this study collected key steps in making APD water and wastewater projects successful. All of the findings from the interview phase were validated by seven public agency executive decision-makers of water and wastewater industries.FindingsOne major study finding was that executive decision-makers chose the APD method because it provided cost and schedule benefits and the owner could also choose the designer or builder based on qualifications. The study also found that the main obstacles executive decision-makers faced were: (1) difficulty in implementing APD methods because they do not follow the low-bid process, (2) reluctance to use DB/CMAR because of the status quo and (3) unfamiliarity of city councils/elected commissions with the DB/CMAR process. The validation survey found that most findings from the initial phase of interviews were confirmed by the executives who took part in validation phase.Research limitations/implicationsThe major limitation of this research is the small sample size. As the executive decision-makers are very hard to reach for interviews, the authors failed to get interviews from a large number of them, despite repeated efforts made by the authors. Another limitation of this study is that the authors contacted most of the executive decision-makers listed in the WDBC list. These executive decision-makers worked for public agencies and, therefore, the views from private agencies could not be included in this research. The authors understand that the validation of the study findings is very important. However, due to the scope and limited time available for the research, the authors could not validate the findings of this study with other public agencies.Practical implicationsSelecting APD methods instead of DBB methods in water and wastewater projects for public agencies is a crucial issue during the project planning phase. Agencies' executive decision-makers need to understand the advantages and disadvantages of APD methods, along with the transition process in order to smoothly deliver projects. The findings of this study will assist public agency executive decision-makers to mitigate risks, overcome obstacles and become more educated about the APD method process, so that these projects can be successfully delivered within budget and on time.Originality/valueThis paper contributes to the existing body of knowledge by identifying lessons learned related to various APD method issues, which can be utilized by municipal executive decision-makers to successfully complete future APD projects.
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