A large steel through truss bridge carries Illinois State Highway 17 across the Illinois River south of the Peru-La Salle area and north of the Peoria area. This farming community sees relatively little traffic. In fact, despite an extensive web search, it seems that relatively little ever happens in Lacon. So, if you have something to say about Lacon, and want to see it in electronic print, please let me know about it.

This style truss bridge is called a continuous truss as opposed to a simple truss. A simple truss has two piers, one at each end point. A continuous truss has 3 or more piers. In the case of the Lacon Bridge, it has 4 piers, one on each end, and two mid-channel. The continuous truss bridge is one rigid structure that spans more than 2 piers. In contrast, we often see simple trusses mounted back to back across 4 to 6 piers, as in the Henry Bridge just up stream. The continuous truss can be built with longer main channel spans than simple truss bridges, so they are used in cases where you want a wide navigation channel. There are many continuous truss bridges over our major rivers, but they have the disadvantage that they are costly to maintain. As a result, new bridges are being built using the cable stayed method (like the Clark Bridge in Alton) or the post-tension concrete segment method (like the new I-35W Bridge in Minneapolis).