Trowbridge Rd. / Grand TrunkCounty: Oakland
City/Township: Bloomfield Hills
Location: Trowbridge Rd. / Grand Trunk
Year Built: 1930 About this Bridge: The Trowbridge Road Bridge is eligible for the National Register as a representative product of a massive engineering project that affected developmental patterns in Detroit and associated communities to the northwest. The Trowbridge Road Bridge is also noteworthy for its false-arch design. The Trowbridge Road Bridge was built as part of a major reconstruction of Woodward Avenue a few blocks to the west. Woodward was among the first improved roads in the state. Made into a corduroy road in 1817, it extended northwest from the nascent town of Detroit to Six Mile Road. When Pontiac was founded further to the northwest two years later, the trip from there to Detroit took two days. The city and county consistently improved the route, and some parts were paved with concrete for the first time in 1915. But by the late 1910s, pressure was building to significantly upgrade Woodward Avenue from downtown Detroit to Pontiac. During this period, Detroit expanded its municipal boundary from Six Mile Road to Eight Mile Road. The city made plans to widen and pave Woodward in this section, but as Wayne County Road Commissioner Edward Hines noted: "No sooner has an improvement . . . taken place than the road immediately becomes congested." In addition to burgeoning commuter and pleasure traffic, many of the automobiles produced in Pontiac and Flint were driven to dealers. Hines concluded: "All the history of the past shows that our failures have been due to underestimating the future rather than in overshooting the mark." In an aggressive move to get ahead of the demand, the road commissions of Wayne, Oakland and Macomb Counties, together with the Rapid Transit Commission of Detroit and affected local governments, coordinated their efforts to create a region-wide master plan for road improvements. In 1923, they succeeded in getting the state legislature to pass the "Wider Woodward Avenue Bill," which committed the state to share with adjacent communities the costs of transforming Woodward into a "superhighway" between Detroit and Pontiac. The state highway department's 1931-1932 biennial report describes the many impediments it faced while procuring the necessary 200-foot-wide right-of-way: "The Department has been confronted with almost every conceivable obstacle in the widening of this highway, including the removal of scores of business blocks and residences in Royal Oak, the moving of portions of three cemeteries in Ferndale, the shifting of 7-1/2 miles of Detroit United Railway tracks and the removal of the 9 mile section of the Grand Trunk Western Railroad between Royal Oak and Bloomfield Center. By far the biggest obstacle encountered was the removal of the Grand Trunk Railroad to a location approximately three-fourths of a mile east." The railroad only agreed to cooperate after a lively legal and political battle. Then, lawsuits from Oakland and Wayne Counties challenged the constitutionality of the arrangement, which was finally resolved in the state's favor by the U.S. Supreme Court in March 1930. Excavation for the tracks began even before the court case was settled. The Birmingham Eccentric reported on 12 September 1929 that 150 men were digging a 55-foot cut, "the longest in any section," at Trowbridge Farm. At the same time, the state and railroad worked on plans for the eighteen grade separations required by the project. The designs were apparently prepared by the railroad, since they are unlike standard highway department construction of the period. A. Guthrie & Company, a contractor from St. Paul, Minnesota, finished sixteen of the structures in 1930, but did not complete the Trowbridge Road Bridge until fall 1931. Ultimately, the relocation of the railroad tracks cost about $7 million. Most of the grade separation structures built as part of the Grand Trunk project carried the railroad over vehicular traffic. In only a few cases did a road pass over the tracks, and most of these structures have experienced significant modifications that have damaged the integrity of their original design. The Derby Street Bridge, also in Oakland County, is another of the rare well-preserved products of the Grand Trunk project, and it, too, is eligible for the National Register.