Sigler Rd. / I-75

MDOT Historic Bridge Monroe County Sigler Rd. / I-75

County: Monroe

City/Township: Berlin Twp.

Location: Sigler Rd. / I-75

Year Built: 1954

About this Bridge:
The four-span Sigler Road Bridge crosses six lanes of I-75 and a median. Piers are concrete with three arched openings. The two-lane-wide deck is carried by six T-beams. The structure is located in a rural area a few miles south of the Wayne County line.

Built in 1954, this structure was one of several grade separations constructed in Monroe County for the Detroit-Toledo Expressway. The contract price for this bridge project was $137,610.93. The new expressway was part of the state highway department’s emphasis on trunkline improvement and expressway development in the period which followed World War II.

The Detroit-Toledo Expressway was not the first important north-south road to traverse the eastern section of Monroe County. The Dixie Highway became the first highway in Michigan in 1829. This dirt road had long been an Indian trail. Located essentially parallel to the current I-75, the Dixie Highway was the main route between Detroit and Toledo until the early 1920s, when Telegraph Road was built a short distance to its west. Both roads are still in use, but have mainly carried local traffic since the opening of I-75 in 1956.

It was hoped that the new expressway would relieve some of the heavy truck traffic clogging Telegraph Road. Although I-75 does not follow exactly the route of either of the earlier roads, the importance of traffic flow through the corridor is evident. Survey work for the new expressway was completed by June 1952, and bridge work on the approximately 25-mile route began during the 1953-54 biennium. The road bed and bridges and grade separations were designed to allow for the future addition of a third traffic lane in each direction. Of the interstate highways being built outside of the Detroit metropolitan area, the routes for I-75 and I-94 (Detroit to Chicago) were the furthest toward completion by the mid-1950s.

Along with its importance as an early expressway structure, the Sigler Road Bridge is also structurally significant. The state highway department first issued standard plans for concrete T-beams were being used for greater under-bridge clearance. This structure stands out for its long spans and number of spans, along with the very good historical integrity which has been maintained.