MoDOT Hires Bridge Engineering Firm TWM to Revamp 3 Bridges

MoDOT Hires Bridge Engineering Firm TWM to Revamp 3 Bridges

April 2017 – MoDOT Bridge Division trusted TWM, a bridge engineering firm serving the greater St. Louis region and Southern Illinois, to tackle replacing three bridges in Stoddard County. This was TWM’s first project for MoDOT’s Bridge Division.

These bridges were formerly on the critical bridge list as being structurally deficient. Surprisingly, the U.S. has around 61,000 structurally deficient bridges according to The American Road and Transportation Builders Association (ARTBA). Thankfully, MoDOT has an effective ongoing program to rehabilitate Missouri’s bridges.

Scoring a 4.8 out of 5 on its performance review, TWM is proud to have served MoDOT on this project. MoDOT’s Structural Liaison noted that TWM did a great job presenting several options for each bridge, and she was appreciative of TWM’s responsiveness and attention to detail.

“The plans were in excellent shape when turned in! This is especially impressive considering it was their first set of MoDOT bridge plans,” she said.


  • Bridge #1: TWM maintained existing profile grade for each bridge by choosing shallow superstructure types when necessary. This design decision minimizes the work required to tie approach roadways into a new bridge.
  • Bridge #2: One design featured shallow solid slab beams with MoDOT’s typical pre-stressed deck panel stay-in-place forms as opposed to the standard reinforced concrete slab superstructure.  Both superstructure types would have provided the shallow superstructure required at this location, but the reinforced concrete slab would have required temporary support during construction, increasing costs and road closure time for construction.
  • Bridge #3: TWM’s structural and hydraulics engineers collaborated to determine that the existing bridge opening was larger than required. We found the new bridge could be nearly 40 feet shorter than the existing bridge which saved tax payers’ money.
  1. Completed preliminary and final designs in just 5 ½ months.
  2. The similarity of 2 of the bridges allowed for efficiency in design to keep MoDOT’s budget as small as possible. Many of the same details were used on both bridges.
  3. TWM exceeded the DBE goal of 8%.  Actual DBE utilization was approximately 34%.

Click here to learn more about TWM’s bridge engineering projects.

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