| Key Facts |
| Bridge Name | Facility Carried / Feature Intersected | Location | Structure Type | Construction Date / Builder or Contractor |
| Speaker Road Bridge
| Speaker Road Over South Branch Mill Creek | Rural: St. Clair County, Michigan | Metal Pinned Parker Pony Truss, Stationary | 1908 By: Unknown |
| Technical Facts |
| Structure Length | Roadway Width | Main Spans | Approach Spans |
| 70 Feet (21.3 Meters) | 14.75 Feet (4.5 Meters) | 1 | None |
An otherwise plain and ordinary rural road is made important and interesting by this highly unusual five panel steel pin-connected Parker truss, which is an extremely rare find in Michigan. A Parker truss bridge is a modification of the Pratt truss. While the bridge has been somewhat modified, with added railings, and additional diagonal member rods added, the bridge is nevertheless an extremely important metal truss bridge in Michigan due to its rare design.
The Michigan Historic Bridge Inventory provides the following details on the bridge: The truss features the following members: upper chord: back-to-back channels with cover plate and battens; lower chord: two looped bars; verticals: back-to-back channels with v-lacing; diagonals: two looped bars; counters: looped square-section rod; floor beam: I-beam connected to superstructure with U-bolt; stringers: I-beam; bottom lateral: round-section rod.
Although modern railings replaced the originals on most of the bridge, the original lattice railings remain on the abutment wing walls. The west end of the bridge features concrete abutments. The east end features steel pile abutments with sheet steel back and wing walls. The bridge has rusted in the past, and the most recent coat of paint, which is wearing out, merely covered up this past deterioration. Despite this, the bridge remains a structure for which preservation remains feasible.
The deck is wood with an asphalt wearing surface on top. On this bridge, the asphalt is wearing off and the pattern of the wood is clearly visible. A weight limit was posted for ten tons prior to closure.
No plaque remains on this bridge, although holes on the end post where it was once mounted are visible.
This bridge faithfully served vehicular traffic on Speaker Road for nearly a century, 99 years to be exact. The bridge saw the last car pass over it when St. Clair County Road Commission closed the bridge to all traffic in August, 2007. The bridge is already slated to be replaced in 2008. Calhoun County Road Commission is supposed to receive the parts for the bridge for eventual re-erection in Historic Bridge Park.
It is worth noting however, that the Speaker Road Bridge could have and indeed should have instead been restored to continue to carry light vehicular traffic in its original location. This solution would have left the bridge in its historically correct location, and also would have ensured that the thumb area, which is relatively devoid of truss bridges, retained a rare truss bridge. However between the inefficient way that transportation funding works in the United States, as well as a lack of genuine interest on the part of the road commission to preserve any of the rarest bridges in the county, this option was not really ever considered. The fact that other Michigan counties, including Kent, Calhoun, Allegan, and Washtenaw all have preserved truss bridges, while St. Clair County lacks even one preserved example suggests that there are also issues at the local level of road agencies that needs reform beyond simply blaming the way money is allocated from higher levels of government. People who find the lack of historic bridge preservation disturbing are encouraged to contact lawmakers and officials and express support for preservation. It is clear that any expression of support should be directed at all levels of government, from Federal to Local.
