|Bridge Name||Facility Carried / Feature Intersected||Location||Structure Type||Construction Date / Builder or Contractor|
Currie Parkway Bridge
|Currie Parkway Over Tittabawassee River||Midland: Midland County, Michigan||Metal Pin-Connected Pratt Through Truss, Fixed||1908 By: Joliet Bridge and Iron Company of Joliet, Illinois|
|Rehabilitation Date||Main Span Length||Structure Length||Roadway Width||Main Spans||Approach Spans|
|1994||140.8 Feet (42.9 Meters)||140.8 Feet (42.9 Meters)||14 Feet (4.3 Meters)||1||0|
The Currie Parkway Bridge is an eight panel pin-connected truss bridge built by the Joliet Bridge and Iron Company, who built a number of truss bridges in Midland and Saginaw Counties.
This bridge has been recognized as a state historic site, and even has a full-size Michigan historic site interpretive plaque placed, something which only a few of Michigan's historic bridges have. Interpretive plaques are important because they help raise public awareness of the existence and importance of historic bridges.
This bridge was rehabilitated as part of preservation efforts in 1988. This makes it one of the earlier truss preservation projects in Michigan. This fact is apparent in the form of rehabilitation that took place on the bridge, which included adding a structural arch to support traffic loads, rendering the truss decorative (non-structural). Supplemental arches, which tend to show up in older preservation projects, have been one way to rehabilitate a historic bridge, although their use is generally considered a compromise preservation solution because while the added arch can increase the load capacity of the bridge and reduce project costs, the arch changes the appearance of the bridge significantly (the arch is hard to ignore when viewing the bridge), and also removes and/or alters significant portions of the original bridge material and design. With the Currie Parkway Bridge, one unusual and invasive alteration was that the entire bottom chord connection assemblies were destroyed as part of the rehabilitation, and the bottom chord eyebars were then welded directly to the vertical members about a foot higher. This is an unusual alteration that resulted in a significant loss of original bridge material and design, thus having an adverse affect on the historic integrity of the bridge.
Despite alterations, the bridge remains an attractive historic bridge that traffic continues to flow over. The bridge actually carries a fairly high volume of traffic for a one-lane bridge, with an Average Daily Traffic of 4,550. Structurally, the bridge is sound, largely because its supporting arch is not old. However, the bridge has an extremely low 1% sufficiency rating, likely a reflection of its traffic volume and one-lane design. The addition of traffic-controlling stoplights at each end of the bridge would be one way to help address this problem. Another solution would be to construct a one-lane bridge parallel to the historic bridge to form a one-way couplet of bridges.
Information and Findings From Michigan Historic Sites Online
The Upper Bridge is a single-span, 140 foot long, steel Pratt through truss with pinned eye-bar connections, and rests on concrete abutments. The bridge has a twelve-foot wide deck and latticed railings.
Statement of Significance
The Upper Bridge is a single-span, 140 foot long,
steel Pratt through truss with pinned eye-bar connections, and rests on
concrete abutments. The bridge has a twelve-foot wide deck and latticed