It took more time to design the plan than to actually construct the bridge.
The Sanyuan Bridge in Beijing links 48 key routes and three major highways: the Airport Expressway, the China National Highway 101 and the 3rd Ring Road. Over 200,000 vehicles cross the bridge daily, so there were some major safety issues when it was discovered that the bridge was severely damaged due to the daily wear and tear from the hundreds of thousands of cars.
Engineers and city planners racked their brains in order to figure out the best and least intrusive way to overhaul the bridge in the fastest amount of time. It took 11 different iterations of the plans and countless hours of painstaking preparation, but the deconstruction of the old bridge and construction of a new one took only 43 hours to complete.