Extension Road
Carrying Extension Road over US 60
6.90 mi E Jct I 10, Maricopa, Arizona
FHWA NBI inspection record for this structure. Condition ratings, inventory load rating, span, deck width, and average daily traffic refresh annually with each NBI release.
Bridge Snapshot: Extension Road
The Extension Road bridge in Maricopa, Arizona carries Extension Road over US 60. It was built in 1978, making it 48 years old today. The structure is built primarily of prestressed concrete continuous. Daily traffic averages 234,822 vehicles, placing it in the heavily-trafficked tier of Arizona bridges.
The latest FHWA inspection records show limited component ratings on file on the 0–9 NBI scale, where 9 is excellent and 0 is failed. The weakest component sits in unrated condition, which drives the overall status of this bridge. No major component scores in the poor range, so the bridge is not classified as structurally deficient under federal criteria.
In a county that maintains hundreds of NBI-tracked bridges, Extension Road is one data point in a Arizona inventory that FHWA inspects on a two-year cycle (more often when ratings fall). Bridge age alone is not a reliable safety signal — a 48-era structure can outperform a newer one when maintenance is consistent, materials are sound, and traffic loads stay within design limits. Use the condition ratings above, the sufficiency score, and the structurally-deficient flag together to read the bridge's real status, and check the linked county and state pages to see how this bridge ranks against its peers.
Every figure on this page comes directly from the Federal Highway Administration National Bridge Inventory (NBI), the public dataset that catalogs more than 617,000 highway bridges across the United States and is updated annually from the records that each state Department of Transportation submits to the FHWA. The condition codes use the standardized FHWA Recording and Coding Guide, the same scale that determines federal eligibility for the Highway Bridge Program and the Surface Transportation Block Grant set-aside for off-system bridges. A "structurally deficient" classification under those federal criteria is a maintenance and funding flag, never a closure order; states keep deficient bridges open with load posting, weight limits, or accelerated inspection cycles until rehabilitation or replacement is funded. See our methodology for refresh cadence and the exact NBI release vintage powering each record.
How Extension Road compares
NBI inventory load rating (metric tons) and structural-deficiency status compared across Arizona, computed live from the FHWA NBI.
Condition Ratings
Ratings are on a 0–9 scale: 9 = Excellent, 7–8 = Good, 5–6 = Fair, 3–4 = Poor, 0–2 = Critical/Failed. Sufficiency rating (0–100) combines structural adequacy, functional obsolescence, and essentiality.
Structural Details
- Year Built
- 1978
- Material
- Prestressed Concrete Continuous
- Avg Daily Traffic
- 234,822 vehicles/day
- Structure Number
- 01873
Location
Data Source
Data from the FHWA National Bridge Inventory (NBI). Bridge inspections are required every two years by federal law. Conditions reflect the most recent inspection.
FHWA NBI Program ↗Guides
Frequently Asked Questions
What do the condition ratings mean for Extension Road?
Bridge condition ratings use a 0–9 scale set by the Federal Highway Administration (FHWA). Ratings 7–9 indicate good condition with no significant problems. Ratings 5–6 mean fair condition with minor issues. Ratings 3–4 indicate poor condition requiring repair. Ratings 0–2 are critical, meaning the bridge has serious structural problems. Extension Road in Maricopa, Arizona.
How often is Extension Road inspected?
Federal law requires most highway bridges to be inspected at least every 24 months. Bridges in poor condition or with known issues may be inspected more frequently (every 12 months or less). Extension Road is part of the National Bridge Inventory maintained by the FHWA. With 234,822 vehicles crossing daily, regular inspection is essential.
What does "structurally deficient" mean for a bridge?
A structurally deficient bridge has at least one major component (deck, superstructure, or substructure) rated 4 or below on the FHWA 0–9 scale. This classification does NOT mean the bridge is unsafe for travel — it means the bridge needs repair, rehabilitation, or eventual replacement. Structurally deficient bridges remain open and are monitored. Extension Road is not classified as structurally deficient.
What is the inventory load rating for Extension Road?
The NBI inventory rating is the load level a bridge is rated to carry for an indefinite period, recorded in metric tons. A lower number means the structure is more load-restricted. It is distinct from the FHWA sufficiency rating, a separate 0–100 funding-eligibility score that this dataset does not include.
Who is responsible for maintaining Extension Road?
Bridge ownership and maintenance responsibility varies — bridges may be owned by state DOTs, counties, cities, railroads, or federal agencies. The FHWA oversees the National Bridge Inventory program and sets inspection standards, but day-to-day maintenance falls to the owning agency. If you notice damage or safety concerns, contact your state DOT or call 911 for emergencies.
How old is Extension Road and does age affect safety?
Extension Road was built in 1978, making it 48 years old. Bridge age alone does not determine safety — condition depends on materials, design, traffic load, maintenance history, and environmental exposure. Many older bridges remain in good condition due to regular maintenance and reconstruction.
Disclaimer: Bridge condition data is from the FHWA NBI and reflects the last reported inspection. A structurally deficient rating does not mean a bridge is closed or unsafe for travel — it indicates the bridge requires repair or replacement. For current closure or safety information, contact your state DOT.
Read our methodology — how this data is sourced, computed, and verified.
Related
| Publisher | Kiznis Studio |
| Sources | FHWA National Bridge Inventory, public U.S. government datasets |