Colorado Bridges
8,965 highway bridges across 64 counties · NBI 2024 data
About Colorado's Bridge Infrastructure
Colorado maintains 8,965 highway bridges across 64 counties, forming critical links in the state's transportation network. With an average construction year of 1982, the typical bridge in Colorado is approximately 44 years old—5 years newer than the national average of 49 years. The state's oldest bridge dates back to 1887, representing over a century of service and offering a window into historic bridge engineering practices.
Currently, 4.8% of Colorado's bridges are rated in poor condition, better than the national average of 6.8%. This indicates relatively strong investment in bridge maintenance and replacement programs. A "poor" condition rating indicates significant deterioration requiring attention, though these bridges remain safe for travel at their posted limits. Federal regulations require bridge inspections at least every 24 months to ensure public safety.
Bridge conditions in Colorado reflect decades of infrastructure investment decisions shaped by geography, climate, traffic demands, and available funding. Bridges here carry 9,663 vehicles daily on average—21% higher than the national average—placing greater demands on structural maintenance. The state's 86,348,671 total daily bridge crossings underscore how essential this infrastructure is to daily commerce and commuting.
The material composition of Colorado's bridge inventory reflects regional construction practices and evolving engineering standards. The predominant construction material is steel, accounting for 32.4% of all structures. Material choice affects maintenance requirements, expected lifespan, and vulnerability to environmental factors specific to the region. Understanding these patterns helps transportation planners allocate resources effectively and prioritize infrastructure investments.
Worst-Rated Bridges
View all 432 poor-condition bridges →432 of 8,965 Colorado bridges have a rating of 4 or below. Rating 4 = advanced deterioration.
| # | Bridge | Rating | Location | Built | Daily Traffic |
|---|---|---|---|---|---|
| 1 | 144TH AVENUE over LOST CREEK Critical condition requiring immediate attention. Built 66 years ago, approaching the end of typical service life. | 0 | Adams County Co. · 1.2 MILES WEST OF SH 79 | 1960 | — |
| 2 | County Road 79.0 over Salado Creek Critical condition requiring immediate attention. Low-traffic rural crossing. | 0 | Las Animas County Co. · 2.8 Mi N of CR 64 | 2020 | 2 |
| 3 | County Road GG over Hell Creek Critical condition requiring immediate attention. Low-traffic rural crossing. | 0 | Washington County Co. · 1.9 Mi. N. of Co. Rd. 27 | 1985 | 8 |
| 4 | SH6 DITCH RIDER RD over BURLINGTON CANAL SR Critical condition requiring immediate attention. Built 78 years ago, approaching the end of typical service life. Serves 19,000 vehicles per day. | 1 | Adams County Co. · 0.7 MI N OF JCT SH 224 | 1948 | 19,000 |
| 5 | COUNTY ROAD 27 over ARKANSAS RIVER Critical condition requiring immediate attention. At 119 years old, this is among Colorado's oldest structures. Low-traffic rural crossing. | 1 | Fremont County Co. · .1 MI N OF US 50 | 1907 | 41 |
| 6 | SLATE RIVER ROAD over NO DATA ENTERED Critical condition requiring immediate attention. Low-traffic rural crossing. | 2 | Gunnison County Co. · 8 MILES NW CRESTED BUTTE | 2006 | 15 |
| 7 | FOREST ROAD 305 over M THOMPSON CR Critical condition requiring immediate attention. Built 70 years ago, approaching the end of typical service life. Low-traffic rural crossing. | 2 | Pitkin County Co. · 7.8 MI SW OF CARBONDALE | 1956 | 10 |
| 8 | COUNTY ROAD 191 over ARKANSAS RIVER Critical condition requiring immediate attention. At 118 years old, this is among Colorado's oldest structures. | 2 | Chaffee County Co. · .3 MI E of SH 291 | 1908 | — |
| 9 | FDR 360 over SOUTH FORK Serious deterioration affecting structural elements. | 3 | Rio Grande County Co. · 1.2 MI SW OF SOUTH FORK | 1976 | 738 |
| 10 | HOLZWARTH ACCESS R over COLORADO RIVER Serious deterioration affecting structural elements. Low-traffic rural crossing. | 3 | Grand County Co. · West side of park approx | 1982 | 2 |
Bridges by County
El Paso County holds 8% of Colorado's bridges. Las Animas County has the highest deficiency rate.
| County | Bridges ↓ | Condition | Poor | Poor % | Avg ADT |
|---|---|---|---|---|---|
| El Paso County Largest bridge inventory in Colorado. | 686 | 245 408 | 22 | 3.2% | 14,394 |
| Weld County One of Colorado's largest bridge inventories. | 614 | 219 365 | 29 | 4.7% | 6,419 |
| Larimer County One of Colorado's largest bridge inventories. Below-average deficiency rate. | 559 | 200 333 | 11 | 2.0% | 7,343 |
| Adams County High-traffic area averaging 21,074 vehicles per bridge daily. | 535 | 191 318 37 | 37 | 6.9% | 21,074 |
| Jefferson County | 464 | 166 276 29 | 29 | 6.2% | 18,194 |
| Denver County Below-average deficiency rate. High-traffic area averaging 40,997 vehicles per bridge daily. | 458 | 164 273 | 8 | 1.7% | 40,997 |
| Arapahoe County Poor condition rate significantly above state average. | 391 | 140 233 28 | 28 | 7.2% | 19,656 |
| Mesa County Below-average deficiency rate. | 319 | 114 190 | 5 | 1.6% | 4,717 |
| Boulder County Below-average deficiency rate. | 311 | 111 185 | 7 | 2.3% | 10,249 |
| Pueblo County | 264 | 94 157 | 12 | 4.5% | 8,361 |
Infrastructure Profile
| Average bridge age | 44 years |
| Average year built | 1982 |
| Oldest bridge | 1887 |
| Newest bridge | 2024 |
| Avg daily traffic/bridge | 9,663 |
| Total daily crossings | 86.3M |
Colorado vs. National Average
Inspections typically occur every 24 months. Structurally deficient does not mean unsafe.