Bridge rehabilitation is priced against drawings of a structure that has been carrying traffic, weather and chloride for decades. The plans describe what the designer expects to find. The bid is a bet on what is actually there. Before you commit a number, get answers to these five questions.
One: what has been inspected, and how recently?
A recent in-depth inspection with element-level condition data is worth more than a thicker set of plans. Ask for the inspection report, the underwater inspection if the structure crosses water, and any material testing from the deck or bearings. If the report is five years old, price the uncertainty.
Two: what is the load path during demolition?
Removing a deck or replacing bearings changes how the structure carries load. Ask how the engineer intends to maintain stability during each stage, and confirm that the temporary condition is shown on the plans. If the contractor has to design the temporary works, the bid needs to reflect it.
Three: what does the traffic control actually require?
A lane closure on a low-volume road is a different problem from a closure on a state route with a peak-hour restriction. Confirm the permitted closure windows, the detour length, emergency access requirements and whether the owner expects night or weekend work. Traffic control can easily exceed ten percent of the contract value.
Four: what is the condition of the bearings and substructure?
Deck replacement often reveals deteriorated bearing seats, cracked pedestals or corroded anchor bolts. Ask whether the scope includes bearing replacement and column repair, and whether those quantities are estimated or measured. Unit-price items for concrete removal and repair are a better risk allocation than a lump sum with an unclear basis.
Five: how will the owner handle changed conditions?
Every rehabilitation project finds something. The question is whether the contract has a clear process for documenting and pricing it. A differing-site-conditions clause, agreed unit rates and a defined review period protect both parties. Without them, the project spends its schedule arguing about paperwork.
The bid is a risk document
The lowest bid is not always the cheapest project. A contractor who has priced the temporary works, the traffic control and the likely repairs is giving the owner a more useful number than one who has priced the drawings and hoped. Owners can encourage that behavior by requiring a means-and-methods narrative with the bid and by evaluating the assumptions, not just the total.
