Illinois
Bridge Design
Design of new and replacement bridges, from private driveway crossings to municipal and DOT bridges.
What the work involves
Bridge engineers design the superstructure, substructure and foundations, coordinate hydraulic and scour analysis, and prepare plans that meet AASHTO specifications for public bridges. Private driveway, farm and trail bridges also need engineering for vehicle loads, including fire trucks, and for flood levels. Prefabricated bridges still need engineered abutments and foundations.
Local conditions we plan for
- Frost depth and freeze thaw damage
- Riverine flooding (Mississippi, Illinois rivers)
- Soft lake clays and deep foundations in Chicago
- New Madrid Seismic Zone exposure in southern Illinois
Building code: No statewide IBC/IRC; codes adopted by local jurisdictions (ICC adoption chart, April 2026).
When you need it
- Replacing a structurally deficient bridge
- New private driveway or farm bridge
- Pedestrian or trail bridge
- Widening or rehabilitating a bridge
Frequently asked questions
How much does bridge Design cost?
Across the US, bridge Design usually costs $10,000 to $500,000. Estimate. Small private and pedestrian bridges are at the low end; public highway bridges much higher.
How long does bridge Design take?
Plan on 3 months to 2 years from signed proposal to stamped deliverables, longer if a site visit, soil testing or a permit review cycle is involved.
Do I need a licensed PE for bridge Design?
In most US jurisdictions, yes. When the work needs a permit, the plans, calculations or report usually must be sealed by a Professional Engineer licensed in the state where the project is located. Every deliverable we issue for permit is sealed that way.
How do I verify an engineer's license in Illinois?
Engineers practicing in Illinois are licensed by the Illinois Department of Financial and Professional Regulation (IDFPR), Professional Engineering Board. You can confirm a license number and its status in the board's public license search before you sign a contract.
Which building code applies in Illinois?
No statewide IBC/IRC; codes adopted by local jurisdictions (ICC adoption chart, April 2026). Cities and counties can add local amendments, which is one reason to hire an engineer who works in your area.
What site problems do engineers see most in Illinois?
Common issues include frost depth and freeze thaw damage, riverine flooding (Mississippi, Illinois rivers), soft lake clays and deep foundations in Chicago and new Madrid Seismic Zone exposure in southern Illinois.