Life-cycle cost analysis (LCCA) is increasingly gaining recognition by the transportation community as an indispensable practice if the sustainability of its infrastructure systems is to be realized. The product of a 3-year study that assessed the LCCA practice in state highway agencies (SHAs) is presented. The study examined how LCCA practice changed in two decades, surveyed the way LCCA is practiced currently at SHAs in the United States, and reviewed how this evaluation technique is deliberated by the academics and researchers in the engineering and economics domains. Results of this study prove noteworthy in the inspection of an observed gap between the state of the practice and state of the art of LCCA. After all, that gap set up grounds for the noted mistrust in the credibility of LCCA. In addition to study results, an analysis of the observed gap and its causes is presented as well as recommendations for what can be done to bridge that gap. It is hoped that this will prove valuable for practitioners conducting LCCA, for policy makers, and for researchers carrying out studies on various topics related to LCCA.

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Subway tunnel condition assessment presents significant challenges for engineers and managers and is becoming increasingly important as the systems continue to age. Tunnels are in constant heavy use in an aggressive environment. Tunnel systems are vast, dark, and noisy. The national investment in subway tunnels is enormous, and careful maintenance and management are necessary to protect this investment. Technologies that can rapidly and accurately access the condition of subway tunnels without interfering with the normal operation of the system were studied. First, issues and problems in subway tunnel maintenance were reviewed through the literature and by interviewing transit agency managers and engineers. Next, different nondestructive evaluation (NDE) methods including spectral analysis of surface waves, impact echo, ground-penetrating radar, and impulse response were evaluated to determine the advantages and limitations of these methods on different problems like water leakage, corrosion, and cracks in subway tunnel systems. Issues of data and infrastructure management were also considered. NDE technologies have considerable potential for improving the maintenance and management of transit infrastructure. However, to fully realize that potential, further development is needed. It is necessary to distinguish between methods that require interruption of subway traffic from those that do not. Rapid screening NDE methods must be researched to develop clear signals of delamination, moisture-related damage, and other issues of concern. It is also necessary to develop automated procedures to process the vast amounts of data generated during extensive NDE testing. Case studies and demonstration projects must be developed and documented to convince managers of the utility of this approach.

As an implementation strategy of the federal retroreflectivity standards requirement for pavement markings, the New Jersey Department of Transportation (DOT) evaluated its 3-year fixed-schedule restriping strategy, to determine if it is consistent with the actual service life of the pavement markings. The methodology and results of the study are presented. Two types of data were collected: measured retroreflectivity by using LaserLux and subjective ratings from a survey conducted with the participation of the New Jersey driving public along a 32-mi circuit. Multiple regression techniques were used to correlate the average scores reported by the study participants for each specific roadway section with the corresponding measured retroreflectivity. The results suggested that the threshold value of an acceptable versus unacceptable level of retroreflectivity appeared to be between 80 and 130 mcd/m2/lux for New Jersey drivers younger than 55 and between 120 and 165 mcd/m2/lux for drivers older than 55. These results are consistent with conclusions reached by other investigators in similar research, where results generally ranged between 70 and 170 mcd/m2/lux. Interim visibility indices were developed for each age group per pavement-marking type. New Jersey DOT used the indices to determine and prioritize needs and to quantify needed related resources, on the basis of the threshold between acceptable retroreflectivity and unacceptable retroreflectivity, when it developed its pavement-marking management system. This approach also allows for cost-benefit and life-cycle analysis for different pavementmarking materials.