The Michigan Department of Transportation (MDOT) is on a mission to preserve and maintain all of the state’s movable bridges, MDOT Bridge Management Engineer Rebecca Curtis told TI News Daily this week.
With 12 movable bridges in MDOT’s current inventory, Curtis said the state’s movable bridges are unique not only from an engineering standpoint, “but also in that they represent large capital investments.”
"[In fact], because of the significant preservation and rehabilitation costs, it is MDOT's goal to preserve and maintain all of the movable bridges in a continuous state of good condition,” Curtis said.
For instance, the US-31 bascule bridge in Charlevoix, which was built in 1949, requires periodic and ongoing maintenance to continue operating properly, James Lake, an MDOT North Region Communications representative, told TI News Daily.
“Since it’s the only crossing of the Round Lake/Lake Charlevoix inlet and the shortest state highway detour is 47 miles, it’s vital that we keep this bridge in good operating condition,” Lake said.
Lake explained that US-31 in this area is an important corridor for tourism and is one of the largest economic drivers of northern Michigan.
The overall US-31 bascule bridge project is expected to cost $1.3 million, funded with a combination of state and federal bridge funds, with completion scheduled for the end of 2016.
Such projects are preferred by MDOT rather than replacing movable bridges. Curtis said the department is focused on capital preventive maintenance (CPM) and rehabilitation work -- all of which is done in-house.
“This translates to a commitment to perform less-costly and less-intensive work on these bridges but at more frequent intervals,” Curtis said.
Each year, MDOT performs a routine inspection on every movable bridge as well as a detailed, in-depth inspection of two movable bridges.
“That means every movable bridge has an in-depth inspection performed once every six years,” Curtis said. Findings from the inspections help MDOT determine what work a bridge will need next and when it should be done.
“A general rule of thumb is that we anticipate a construction project about once every 12 years or so to keep the bridge in good structural and operational condition,” Curtis said.
However, many factors contribute to when MDOT actually works on a bridge, such as the condition, funding availability, other projects in the vicinity, etc., Curtis said.
“MDOT maintenance crews do a tremendous amount of work on the movable bridges between capital projects and are frequently commended for their excellent work by the consultants who perform the in-depth inspections for us,” Curtis said.
Lake added that overall, the goal of providing good roads, bridges and other transportation infrastructure is a critical component of MDOT’s mission to promote the state’s economy and improved quality of life.
“Without investment in maintaining that system, Michigan’s economy and the lives of our residents suffer increased shipping costs, delays, vehicle maintenance costs and other effects,” Lake said.