of the Fairfield bypass and the completion of the 1996 highway plan. The next year, the Des Moines to Burlington route was given a single route number, Iowa 163, which had previously extended from Des Moines to Oskaloosa. Between Oskaloosa and Burlington, the Iowa 163 number was overlaid atop the existing route numbers, US 63 and US 34. River crossings Upon entering and exiting the state, US 34 crosses a major river—the Missouri River in the west and the Mississippi River in the east. Historically, the highway crossed each river on narrow, two-lane truss bridges. Since the 1990s, both river crossings have been replaced with modern four-lane bridges capable of handling high-speed traffic. The MacArthur Bridge was a cantilever truss bridge that opened in March 1917 as the Citizen's Bridge. The connection from Burlington to Illinois cost $200,000 to build (equivalent to $ in ). The bridge was renamed the MacArthur Bridge in 1923 after J.A. MacArthur, the president of the Citizen's Bridge company. While in service, the toll bridge collected millions in revenue. Some of that revenue was siphoned away from bridge expenses to pay for unrelated projects. That practice ended in 1983 when all tolls were directed to bridge-related expenses only, including construction of a new bridge. Starting in 1974, tollbooth attendants weighed tractor-trailers on either side as the bridge only allowed trucks to cross safely from one direction at a time. An environmental assessment completed in 1986 suggested that the costs of rehabilitating the MacArthur Bridge far outweighed the construction of a new bridge and recommended a cable-stayed bridge design in order to provide a navigation channel. Workers began building the new bridge, the Great River Bridge, in 1988. The Great Flood of 1993 delayed opening of the bridge. The first two lanes opened to traffic on October 4, 1993, and opened fully on August 25, 1994. The new bridge cost $53 million (equivalent to $ in ). The MacArthur Bridge was dismantled shortly after the Great River Bridge opened. On the other side of the state, the Plattsmouth Bridge was also showing its age. The steel bridge was built in 1929 at a cost of $750,000 (equivalent to $ in ). Since opening, the bridge was owned and operated as a toll bridge by the Plattsmouth Bridge Company. Beginning in the 1990s, the Iowa DOT and Nebraska Department of Roads (NDOR) began looking at ways to