Overpass Bridge Costs: What Drives the Price Tag
An overpass bridge costs $1.2M-$45M+ depending on span, material, site, and complexity. There's no "average"—only ranges by type.
Cost Ranges by Span & Material (2024 USD, construction only)
| Span | Steel | Concrete | Typical Use |
|---|
| Short (30m / 100 ft) | $1.5-2.5M | $1.2-1.8M | Local road over highway, rail |
| Medium (60m / 200 ft) | $3-4.5M | $2.5-3.8M | Arterial over freeway, river |
| Long (150m / 500 ft) | $12-20M | $10-15M | Major interchange, wide river |
| Very Long (300m / 1,000 ft) | $25-45M | $20-35M | Cable-stayed, complex interchange |
What's Inside the Number
- Superstructure: Girders, deck, bearings, barriers (40-55%)
- Substructure: Abutments, piers, foundations, piles (25-35%)
- Approaches: MSE walls, embankments, pavement (10-20%)
- Soft costs: Design (8-12%), CM/inspection (5-8%), permitting, utilities, ROW (variable)
Major Cost Multipliers
- Site access: Urban = 1.5-2x rural (traffic control, staging, utilities)
- Foundations: Deep piles (rock, soft soil) = +30-100%
- Skew/curvature: +15-30%
- Aesthetics: Architectural treatment = +10-25%
- Railroad involvement: AREMA standards, flagging, insurance = +20-50%
- Seismic zone: High = +15-30%
- Accelerated construction: SPMT, ABC = +20-40% (but saves user delay costs)
Real-World Examples
- I-405 Sepulveda Pass (LA): $1.6B for 16 km including bridges
- Typical state DOT overpass: $3-8M
- Pedestrian bridge: $500K-5M (lighter, no live load)
Bottom Line
Get a site-specific estimate from a bridge engineer. Rule of thumb: $500-1,500/ft² deck area for standard highway overpasses. But every bridge is a prototype.
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