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Oregon Demonstration Project: Alternate Project Delivery And Accelerated Bridge Construction On OR 38, Drain To Elkton
Project Overview and Lessons Learned
The Oregon HfL project consisted of removing and replacing five bridges on an 11-mi stretch of OR 38 between the towns of Drain and Elkton. These bridges, built in the late 1920s and early 1930s, were near the end of their useful life and required immediate attention. They were selected for replacement under the Oregon Transportation Investment Act State Bridge Program for a variety of reasons, including (1) structural and functional deficiencies resulting in repair costs that exceeded one-half of the replacement cost, (2) substandard bridge width, and (3) load ratings insufficient to carry permit vehicle loads.
After exploring many alternatives and evaluating the project and user costs, ODOT selected the use of the design-build (D-B) method of project delivery in concert with incentive and disincentive clauses that included innovative staged construction and accelerated bridge removal and replacement techniques. Removal and replacement of the bridges on OR 38 was a great success, and ODOT was able to complete the project more than a year ahead of schedule.
Strategies that helped ODOT achieve its goal included the following:
Safety, construction congestion, quality, and user satisfaction data were collected before, during, and after construction to demonstrate that the D-B method of project delivery coupled with innovative accelerated bridge construction (ABC) technologies can be used to achieve the HfL performance goals in these areas.
For ODOT, safety of the workers and the traveling public was more than a performance goal; it was a requirement under the Oregon Transportation Investment Act program. During the construction of the bridges on OR 38, few worker injuries were reported and these injuries were minor in nature. All site personnel, field crews, designers, inspectors, and owner's representatives received site-specific orientation and safety training before working on this project. In addition, all construction workers received quarterly safety training and attended mandatory weekly safety meetings.
During construction, the contractors took extraordinary steps to assure that incidents were kept to a minimum. The many safeguards put in place to prevent crashes during construction were effective. These included procurement of Oregon State Police during major traffic changes and peak construction periods. Other effective measures included scheduled open houses, regular news releases, and establishment of a dedicated phone line and Web site. A review of the individual crashes showed that only three occurred in the vicinity of the project's bridge sites. However, as reported by ODOT, none of the crashes was attributed to the construction activities.
The performance goal established by ODOT on motorist delay was that no vehicle should be delayed by contractor operations more than 20 minutes beyond its normal travel time. The contractor easily met this goal. Based on a travel time study conducted by HfL consultants, a delay of 5 to 9 minutes was computed for each vehicle during daytime hours. For the most part, the approach adopted was to maintain two lanes of uninterrupted traffic throughout the construction period, except for 6 weeks on crossing 5, which required the use of a temporary bridge, and two separate weekend closures for removal and replacement of crossings 3 and 4. The primary focus of the Oregon HfL project was crossings 3, 4, and 5 because of their exceptional complexity and innovative features. For the most part, crossings 1 and 2 were built using traditional methods of construction, so they are not addressed in great detail in this report.
Under conventional construction, the residents and the traveling public using OR 38 would have had to deal with delays, lane closures, and construction activities for well over 3 years. However, with the adoption of an alternate method of project delivery, rapid bridge removal and replacement techniques, and innovative staged construction, ODOT was able to complete the entire project in less than 18 months.
Although the quality of the replaced crossings on OR 38 potentially was improved because the work was done in a controlled environment and prefabricated bridge components were used, the replacement process had no impact on the noise and smoothness of the pavement surface.
Beginning at the project planning stages, ODOT undertook an aggressive and comprehensive effort to communicate with affected residents and businesses along the corridor and near the bridges, keeping them abreast of all activities before, during, and after construction. User satisfaction surveys designed and distributed to neighboring residents by Lois D. Cohen Associates clearly demonstrated a high level of public satisfaction with the construction approach and the final product. ODOT exceeded the HfL customer satisfaction expectation by a large margin.
The benefits and costs of the innovative features of the project were compared with projects of similar size and scope with a more traditional delivery approach. ODOT supplied all of the cost figures for the as-built project and the cost assumptions for the traditional approach.
Based on an economic analysis conducted by ODOT using the StartBENCOST analysis model approach, ODOT realized a total cost savings of about $2.4 million over conventional construction practices. These savings stemmed from reduced construction duration, mobilization costs, reduced delay cost, and the use of innovative bridge removal and replacement techniques. Overall, the savings to ODOT represent about 5 percent of the total project cost.
The removal and replacement of the five crossings on OR 38 was a great success, resulting in a quality project completed substantially ahead of schedule while maintaining freight mobility and reducing impact on motorists, residents, and businesses. Through this project, ODOT gained insight on proven innovative construction features and innovative public outreach practices and learned many valuable lessons that can be incorporated into similar future projects in Oregon. These lessons include the following:
From the standpoint of construction speed, user and agency costs, quality, worker and motorist safety, and community satisfaction, ODOT's project was a great success and unequivocally exemplified the principles of the HfL program. ODOT learned that using the D-B method of project delivery coupled with proven innovative technologies and incentive/disincentive clauses could accelerate construction, lessen the impact on the traveling public and environment, maintain mobility, and improve worker and motorist safety. A postconstruction stakeholder survey conducted by ODOT clearly demonstrated the satisfaction of local residents and businesses with the construction approach and final product.