June 29, 2026
When No One Is Watching: Why Proactive Bridge Inspection Protects the People Who Use Our Trails
By Tom Lohman, PE | Structural Engineering
Most people cross a bridge without a second thought. They’re focused on the view, the ride, or getting to the other side. That’s exactly how it should be. Our job is to make sure the bridge underneath them has earned that trust.
That’s the mindset we bring to every bridge inspection we perform, and it’s the mindset that drives our work with Madison County Transit (MCT) on their trail bridge assessment project.
A Different Kind of Bridge
The bridges we’re inspecting for MCT aren’t your typical highway overpasses. They’re former railroad bridges, repurposed to carry pedestrians and cyclists along a trail corridor. They’re well-used, well-loved, and in many cases, well-aged.
Here’s what makes trail bridges a unique challenge: unlike roadway bridges, which federal law requires to be inspected every two years, trail bridges carry no such mandate. There’s no regulatory clock ticking. No agency knocking on the door. The decision to inspect is entirely up to the owner.
Scale doesn’t determine risk. A timber floorboard that gives way under a cyclist is just as dangerous as a compromised highway girder, and just as preventable.
MCT made that decision proactively. That matters.
If you let the bridges go, you’re going to have some pretty big costs down the line.
Clients appreciate the good engineering service that tells them what they need to do and they know it’s not a wish list. We’ve earned that trust.
What We’re Actually Looking For
A bridge inspection isn’t just a visual once-over. It’s a systematic, element-by-element evaluation of every component that keeps a structure standing and safe.
On trail bridges like these, timber decks and railings are often the first things to go. Wood deteriorates faster than steel or concrete, and when it does, the consequences can be immediate and dangerous. Floorboards can give way. Railings can fail. What looks solid from the trail surface can be compromised underneath. And on bridges with fracture-critical members (non-redundant steel tension members where a single failure puts the entire structure at risk) there’s no substitute for a hands-on inspection. Drones are a valuable supplemental tool, but inspectors need to be within arm’s reach of those critical members. Some things you simply have to touch.
Then there’s pack rust — one of the more deceptive conditions we encounter on older steel structures. Steel corrodes and expands, puffing up in layers. Half an inch of steel can look like four inches of rust. Until you clean it away, you don’t know what’s left of solid steel.
A Bridge Report Only Matters If It Leads to the Right Decisions
When we finish an inspection, we don’t hand over a stack of technical jargon and call it done. The goal is a report that a transit director, a parks manager, or a board member can actually use.
At the end of the day, it’s a bridge inspection and it’s a thumbs up or a thumbs down and a list of a few items. We like to keep things simple and digestible.
Clear condition ratings, prioritized repair recommendations, and dollar figures on every item. Not a wish list. A planning tool. One that lets MCT look three, five, or ten years down the road and budget accordingly, rather than getting blindsided by an emergency repair or, worse, a closure.
That kind of proactive planning also carries a liability dimension. Following a higher standard than is legally required doesn’t just protect the infrastructure; it protects the client. It demonstrates due diligence. It builds public confidence in the system.
An inspection rarely answers just one question. A scoured streambank beneath a bridge raises a water resources question. A deteriorating truss raises a repair-or-replace question. A replacement project brings in roadway design, environmental clearance, and hydraulic analysis. The inspection report is the starting point for all of it. Having that documentation in hand, with clear condition ratings and cost estimates, puts agencies years ahead when it’s time to pursue funding.
The Person on the Other Side
There’s a through line in all of this work that goes beyond load ratings and condition scores. It’s the person crossing the bridge.
I coordinate inspection schedules around school bus routes and emergency vehicle access. I keep in mind the cyclist who crosses at 7 AM and the family walking the trail on a Saturday afternoon. The technical work is rigorous, but the reason for it is human.
That perspective was reinforced during one of the more memorable inspections in my career — the Old Chain of Rocks Bridge, a historic Route 66 structure over the Mississippi River that now serves as a multi-use trail. During our inspection, I met a man who came to the bridge every single day at 3 PM to watch the river. The man eventually shared a photograph taken from the bridge years earlier, when the river was low and you could walk out to the middle of the channel.
It’s awe-inspiring. You meet people from Germany, from England, who traveled specifically to see the Chain of Rocks Bridge.
A bridge is infrastructure. But it’s also memory, community, and connection. Keeping it safe is how we honor all of that.
If your agency manages trail bridges, park bridges, or any structure outside the federal inspection mandate, the best time to start a program is before something forces your hand. A baseline inspection gives you a condition snapshot, a prioritized repair list, and the documentation you need to plan budgets and pursue funding.
Tom Lohman, PE, SE, is Associate Vice President and Structural Business Unit Leader at Horner & Shifrin with 29 years of experience in highway bridge design, inspection, and hydraulic engineering. He is a certified National Bridge Inspection Standards Team Leader and is qualified to inspect nonredundant steel tension members, the fracture-critical structures that demand the highest level of hands-on scrutiny. His work spans MoDOT and IDOT bridge programs, LPA projects, and complex hydraulic modeling across the region.