The main objective of this study is to determine the effectiveness of alternative contracting strategies on aspects of project performance such as schedule and cost, in order to promote ways to apply the strategies effectively. A quantitative analysis that draws on 1,372 infrastructure improvement projects recently completed in California from 2000 to 2008 was conducted to achieve the objective. According to the analysis, alternative projects contracted with I/D and A+B represented 7% of all project establishments and 23% of all project allotment costs. The results of one way ANOVA analyses show that I/D projects held a decisive schedule-saving advantage over A+B and conventional projects, but that I/D also increased project costs significantly more than the others because of a higher frequency of contract change orders. The results of statistical analyses reveal a severe effectiveness problem with use of the A+B contracting strategy. When compared with conventional projects, A+B not only included extreme severe schedule overruns, but it also increased project costs far above the levels seen in conventional projects; both of these resulted from inaccuracies created by allowing contractors to bid on contract time. According to the analysis, the additional cost growth for utilizing I/D was recouped by reduced construction time, but this tradeoff was not seen in A+B projects.

This technical memorandum presents an analysis of the impact of urban freeway pavement rehabilitation on freeway traffic on I-710 Long Beach (CA), a freeway with high traffic volume, over eight 55-hour weekend closures. The study included actual traffic measurements and microscopic simulations through a broad traffic network containing a construction work zone (CWZ), neighboring freeways, and detour arterials. As drivers re-routed to the detour routes, the hourly peak traffic demand through the CWZ during construction weekends decreased by 37 percent from historical averages, which is near the Traffic Management Plan (TMP) average estimate of 40 percent. During construction, traffic volume on arterial intersections was increased noticeably (14 percent), and network-level noshow traffic was insignificant (only 1 percent). As the weekend closures were repeated, drivers exhibited a learning effect, with the maximum peak hourly volume through the CWZ decreasing. The microscopic simulation study experienced some calibration limitations due to the large grid network and high traffic volume, but was found to be sufficiently efficient and reliable to warrant use for validation of TMPs for future highway rehabilitation projects.

In June 2003, The California Department of Transportation successfully completed reconstruction of a 4.4-km stretch of Interstate 710 in Long Beach, the most heavily truck loaded route in the state. The work was a part of a long-life asphalt concrete (AC) pavement rehabilitation project constructed during repeated 55-hour weekend closures with fast-track construction and 24-hour operations. This report presents the overall rehabilitation process and productivity based on construction data monitored at three of the eight weekend closures. Production rates of demolition, aggregate base placement, and AC paving operations received special focus, particularly in terms of variations due to 1) time of day, 2) AC mix design and number of layers, and 3) paving methods. Noticeable effects on productivity related to the learning curve of the construction crew were observed as the weekend closures were repeated. In addition, a traffic measurement study utilizing various traffic surveillance tools was implemented to quantify the impact of construction closures on network traffic delay. This case study will be useful for transportation agencies and contractors in developing integrated construction and traffic management plans for highway rehabilitation projects that maximize construction productivity and minimize traffic delay in high volume situations.