The Town Line Road bridge is the first bridge on the St Louis River to be located east of the US-53 Iron Range Expressway. While the bridge looks to be new, it is actually 20 years old in these photos. That is a testament to how well these prestressed concrete bridges hold up over time. The fresh asphalt overlay on the roadway helps add to the illusion that this is a new road and new bridge.

The bridge is a classic MN-DOT style prestressed concrete girder bridge with a reinforced concrete deck. The bridge is built purely for function, and has no decorative elements. It has two standard width traffic lanes, plus small shoulders on each side of the roadway. The bridge also has the modern style slanted guardrails. The slant helps absorb and deflect the energy of a crash, and the solid design helps keep road debris out of the river.

One interesting feature of the bridge is the low-cost bridge piers. A typical bridge would have solid reinforced concrete piers that are in a T or H shape. The issue is that they require foundations that can disturb the river, and they take time to cure. On this bridge, the low-cost piers are built by driving steel pipes into the ground with a pile driver, then topping off the pipes with a small concrete pier cap. The pipes are good at carrying a highway load, but they are not stable side to side. To make up for this issue, the end pipes are driven in at an angle. This provides more than enough lateral stability. These piers can be driven in a few days, and topped off in less than 2 weeks, as opposed to 4 to 6 weeks to build conventional piers.

The photo above is looking northeast across the deck of the Town Line Road Bridge across the Saint Louis River from near the southwest corner of the structure.

The photo above is looking due east down the center of the bridge deck. The photo below is looking east along the downriver south face of the bridge. The steel piling bridge piers are partially visible in this view.