Ontario’s Ministry of Transportation (MTO) used a rapid replacement technique for the first time in Canada to remove and replace two bridges in 15 hours on the busiest thoroughfare of the Nation’s Capital. On August 11, 2007, the twin structures, 4 lanes and weighing 650 tonnes each, were removed by self propelled modular transporters and replaced with two new structures that were constructed in a nearby staging area. The removal and replacement of the bridges required a complete closure of Highway 417 (Ottawa Queensway). The ultimate context sensitive design converted the bridges to semi-integral abutments, used adjustable bridge bearings and increased worker safety by allowing construction to be performed in a safe environment without exposure to traffic. The design included a full risk assessment and required a coordinated team effort. Experts from the ministry, City of Ottawa, the contractor and representatives of the heavy lift technology and transporters worked together to ensure project success with minimal impact on the environment. What normally would have required two full construction seasons with traditional staging, traffic shifts and delays was completed overnight saving an estimated $2.4M, significantly reducing the length of traffic delays, societal costs and resulting environmental impacts. Although this project did not specifically track vehicle emission levels, theoretical estimates indicate that utilizing rapid bridge replacement technology can reduce hydrocarbon, CO and NO emissions compared to a conventional construction approach. Since the successful completion of the Island Park Bridge replacement, the ministry has awarded the next pair of twin structure removal and replacements at Clyde Avenue and will continue with the removal and replacement of three more twin bridges on Highway 417.