Muhammad Bilal Khurshid

Evaluating the Cost Effectiveness of Flexible Rehabilitation Treatments Using Different Performance Criteria

At a certain point in the life of a flexible pavement, rehabilitation is required to improve pavement condition and to defer reconstruction. Pavement managers seek the best rehabilitation treatment on the basis of cost effectiveness. Using 1994–2002 data from a wet-freeze mid-Western state in the United States, this paper analyzes the cost effectiveness of four flexible pavement rehabilitation treatments: functional hot-mix asphalt (HMA) overlay, structural HMA overlay, resurfacing (partial 3R standards), and mill full-depth and asphaltic concrete overlay. The performance indicator used is the international roughness index and treatment effectiveness is measured in terms of performance jump (short-term), and service life and increase in pavement performance (long-term). The treatment cost is the equivalent uniform annual cost per lane-km incurred by the agency and user; and cost effectiveness is the ratio of effectiveness to cost. The study estimated treatment effectiveness under various combinations of traffic loading and climatic condition, and initial pavement condition. The results suggest that in the short-term, HMA structural overlay is the most effective treatment. For the long-term, the results are equivocal: HMA structural overlay is most effective from the perspective of average performance over the treatment life; resurfacing (partial 3R standards) is the most effective from the perspective of treatment service life. With regard to cost effectiveness, however, the results were consistent: for all three measures of treatment effectiveness, mill full-depth and asphaltic concrete overlay unequivocally appears to be the most cost effective treatment. Finally, the paper recommends that cost effectiveness analysis should be accompanied by a candid deliberation of project constraints, the local environment, and agency practices.

Optimal Performance Threshold Determination for Highway Asset Interventions: Analytical Framework and Application

Civil asset managers continue to seek appropriate thresholds of asset performance for applying standard interventions. Recognizing that between the two extremes of profligacy and parsimony there exists a certain optimal intervention application threshold that is consistent with greatest possible overall benefits at least possible overall costs, this paper develops a framework for establishing such thresholds. The framework dimensions are costs (monetary) and benefits (durability and service life), agency and user cost considerations, and initial and life-cycle contexts. The paper utilizes well-established concepts of cost-effectiveness analysis to address the long-standing conundrum of optimal asset performance threshold determination. The application of the methodology is then demonstrated for a common pavement rehabilitation treatment, and the derived optimal thresholds are compared with those of past practice. The results showed that for this treatment, the past practice is not only inconsistent with optimal practice but is also associated with significant variability thus precluding its suitability for the practice. The developed methodology can be used to establish performance thresholds for various standard interventions not only in the management of transportation assets but also of systems in civil and other engineering disciplines.

Establishing optimal project-level strategies for pavement maintenance and rehabilitation – A framework and case study

This article presents a framework and an illustrative example for identifying the optimal pavement maintenance and rehabilitation (M&R) strategy using a mixed-integer nonlinear programming model. The objective function is to maximize the cost-effectiveness expressed as the ratio of the effectiveness to the cost. The constraints for the optimization problem are related to performance, budget, and choice. Two different formulations of effectiveness are derived using treatment-specific performance models for each constituent treatment of the strategy; and cost is expressed in terms of the agency and user costs over the life cycle. The proposed methodology is demonstrated using a case study. Probability distributions are established for the optimization input variables and Monte Carlo simulations are carried out to yield optimal solutions. Using the results of these simulations, M&R strategy contours are developed as a novel tool that can help pavement managers quickly identify the optimal M&R strategy for a given pavement section.

Multidimensional benefit–cost evaluation of asphaltic concrete overlays of rigid pavements

Using the data from a national study in the USA, this study demonstrated a comprehensive and multidimensional pavement treatment evaluation methodology and used the methodology to evaluate the short-term and life cycle cost-effectiveness (CE) of five rigid pavement rehabilitation treatments. Four measures of effectiveness were used in this study: the sudden decrease in surface roughness, treatment service life, increase in average pavement condition over the service life and the area bounded by the performance curve. This study established relationships that quantify the influence of pre-treatment condition on treatment effectiveness. Also, the models were developed to describe the treatment effectiveness as a function of traffic loading and climatic severity. It is seen that at high traffic loading, there is relatively little difference in treatment effectiveness across various climate severities. This study suggests that superior effectiveness of a treatment does not necessarily translate into superior CE. Also, the treatment location was found to influence the relative effectiveness of the treatments. Overall, the results suggest that treatment ‘crack-and-seat and 8-in. asphalt concrete overlay’ is the most cost-effective.

Estimating national road crash fatalities using aggregate data

Injuries and fatalities from road traffic crashes have emerged a major public health challenge in Pakistan. Reliable estimates of road crash fatalities (RCF) of a country, is a vital element needed for identification and control of key risk factors, road-safety improvement efforts and prioritizing national health. Reliability of current annual RCF estimates for Pakistan becomes highly questionable due to serious underreporting. This study aimed to predict annual RCF for Pakistan using data from World Health Organization and International Road Federation sources. An ordinary least square (OLS) regression model that relates fatality rate with different explanatory variables was developed. RCF were predicted for Pakistan for year 2012 and 2013, and results were compared with national police reported estimates. Study results indicated that there is serious underreporting of RCF in Pakistan and immediate measures are needed to improve the existing road crash recording and reporting system at the national and subnational levels.

Scale and Condition Economies in Asset Preservation Cost Functions: Case Study Involving Flexible Pavement Treatments

Estimates of planning-level treatment costs are vital inputs for preservation project budgeting, prioritization, and programming in highway asset management. However, with the paucity of analytical research on highway asset preservation costing, agencies have resorted to the use of average costs. However, average cost values fail to adequately accommodate the influence of cost factors such as project size and asset condition at the time of the preservation treatment. In addressing this issue, this paper explores the efficacy of different mathematical specifications, including the Cobb-Douglas form and a variety of other nonlinear forms, for developing treatment cost functions. The paper shows how flexible formulations could be used to specify the response variable in order to avoid unduly restricting the models and to yield cost estimates that are more reliable compared to average costs. The paper shows how to investigate the direction and strengths of scale economies and condition economies in highway asset preservation costs using mathematical forms that allow for determining the partial derivatives of treatment cost with respect to asset dimensions and pretreatment condition. The paper demonstrates its concepts by using data on flexible pavement preservation treatments at a midwestern state highway agency.

A framework for assessing the consequences of deferred or hastened highway asset interventions

Application of a treatment at appropriate time is indeed a critical issue in highway asset management. A treatment that is applied too early (hastened) or too late (deferred) has consequences in terms of the agency cost, facility performance and cost-effectiveness. This research uses basic concepts in costing and effectiveness analysis to develop a methodology for quantifying the consequences of mistimed highway preservation interventions. Through a case study on pavement preservation, demonstrating the practical application of the methodology, it is observed that the consequences of hastened or deferred interventions can differ across asset classes as well as across intervention types: the consequent life-cycle cost increases and performance losses are more severe for non-interstate highways compared with interstate highways, and are more severe for maintenance compared with light rehabilitation. Recognising that in the practical world, the timing of interventions need not be at the optimal levels, the paper goes on to show how an agency could use the developed methodology to establish acceptable ranges of intervention timing and introduce flexibility in its preservation schedules by establishing the earliest and the latest times for applying an intervention in order to avoid undue penalties in terms of cost and effectiveness.

Influence of Six Sigma on project success in construction industry of Pakistan

Purpose The purpose of this paper is to investigate the level of implementation of Six Sigma (SS) in the construction industry of Pakistan along with the current state of affairs and the challenges, and opportunities for a successful implementation. Design/methodology/approach The research is purely exploratory in nature. Based on published work, critical success factors are gathered, and a number of questionnaire surveys and interviews are conducted to refine and quantify their impact. A system dynamics framework to assess the SS influence on project success is developed and case study project are simulated. Findings The construction industry of Pakistan is still functioning in a traditional way; marred with low level of awareness and ad hoc approaches, the findings point to a huge improvement opportunity. Further, when under planning projects are exposed to SS, the chances of project success improve better than under execution projects. Research limitations/implications The limited level of awareness possessed by the respondents constrains the possible outreach of this work in industrially developed contexts. However, this work may become an impetus for further research in managing quality in construction industry. Practical implications The findings can be used to improve the quality provision of construction projects. Originality/value This work may trigger an important debate over the research and implementation of SS in the construction industry of developing countries that may greatly benefit by improving the quality of their projects and rectify their diminishing reputation for project success.

Performance Assessment of Construction Engineering and Management (CEM) Degree Program in Developing Countries: Case of Pakistan

ABSTRACT The performance of construction industry is largely supported by the competence and skills generated by Construction Engineering and Management (CEM) programs offered in the country. A review of published literature points to scarcity of studies evaluating performance of curricula with respect to generating the requisite skills. In an attempt to assess the efficiency of CEM programs offered in Pakistan, this study identifies the key knowledge areas, technical skills, and expertise that these programs need to focus on for sufficiently preparing the post graduating students entering modern and complex construction industry. In doing so, two universities (NEDUET and NUST) offering mature CEM program at postgraduate level have been engaged. Based on a questionnaire survey of CEM graduates, employers and academicians, it is found that the program content is adequately designed and delivered by well versed and competent instructors. Generally, a high degree of agreement for technical skills is found among the perceptions of graduates and the expectations of the industry. However, some major challenges are identified which if addressed can help boost the satisfaction level of students. Acknowledging the possibility for improvement, recommendations for curricula updates in order to bridge the gap between academia and industry are proposed.