New Castle Creek Bridge
Aspen's Transportation Future
For more than 30 years, the City of Aspen, alongside our community partners and local government agencies, has been discussing the best transportation options in and out of Aspen – an effort known as the “Entrance to Aspen”. Since the existing Castle Creek Bridge is nearing the end of its lifespan, it’s time to get serious about building a new bridge.
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Get Up to Speed
In the mid-nineties, hundreds of community members worked tirelessly to address traffic congestion and improve air quality through plans for a different Entrance to Aspen. This work was used by the Colorado Department of Transportation (CDOT) as the foundation to create 10 project objectives. These objectives are still being used today to make decisions about the Entrance to Aspen. To meet these objectives, CDOT and the Federal Highway Administration (FHWA) evaluated 43 different alignments and lane configurations, solicited public comment, held an official public hearing open house, and considered comments from 951 letters about what the future of the Entrance to Aspen could be.
- CDOT and FHWA selected one out of 43 alignments that met all 10 project objectives. This is known as the “Preferred Alternative”.
- The Preferred Alternative and key transportation improvements between the airport and Aspen (such as the roundabout and the new Maroon Creek Bridge) are part of a larger document called the Record of Decision (ROD) that was finalized in 1998.
- The ROD was specifically written to include flexibility, welcoming public input on future design elements that would meet community needs and desires.
- What are the past key dates for the Entrance to Aspen?
1961 - The current Castle Creek Bridge was built with a maximum lifespan of 75 years (2036).
1995 - The community, Aspen City Council, Pitkin County Commissioners, Town of Snowmass Village Council, CDOT, and FHWA developed the project need, intent, and 10 project objectives.
1996 - 59% of Aspen voters said, “yes” (41% “no”), to authorize a right-of-way over Marolt and Thomas properties for a two-lane parkway and corridor for light rail with a number of stipulations.
1997 - Final Environmental Impact Statement (FEIS) was completed.
1998 - Record of Decision (ROD) was finalized.
2001 - 54% of Aspen voters said, “no” (46% voted, “yes”), to change the right-of-way over Marolt and Thomas properties for a two-lane parkway and exclusive bus lanes until the community supported light rail funding.
2007 - The reevaluation of the ROD proved the document and plan were still valid.
2007 - Comprehensive community outreach was completed with no clear political consensus on a path forward.
2008 - Roundabout construction was completed.
2009 - BRT lanes were implemented from the airport to the roundabout.
2015 - Rubey Park Transit Center was completed.
2018 - 8th Street bus stop improvements and pedestrian safety improvements were completed.
- What are the 10 project objectives?
Community-Based Planning: An inclusive process focused on limiting vehicle trips to decrease downtown congestion.
Transportation Capacity: Meets future traffic capacity needs, but keeps vehicle trips to the level in 1994.
Safety: Addresses concerns like pedestrian safety and higher-than-average accident rates through the S-Curves.
Environmentally Sound Alternative: Minimizes and mitigates adverse impacts.
Community Acceptability: Fits the character of the community and is aesthetically acceptable to the public.
Financial Limitations: Realistic current and expected funding levels and programs.
Clean Air Act Requirements: Limits vehicle trips to manage air quality in accordance with local and national goals.
Emergency Access: Provides an alternative route over Castle Creek for emergency vehicles to access incidents inside and outside of downtown.
Livable Communities: Keeps within the small town character and scale of the Aspen community, which enhances the quality of life for residents and visitors.
Phasing: Provides phasing so future transit options can be accomplished.
- Who were the project planning partners?
- Roaring Fork Valley Residents
- Aspen City Council
- Pitkin County Commissioners
- Town of Snowmass Village Council
- Colorado Department of Transportation (CDOT)
- Federal Highway Administration (FHWA)
The Preferred Alternative
The Preferred Alternative extends Main Street over a new Castle Creek Bridge and under a land bridge that meets the existing Highway 82 near the roundabout.
- Two general-use lanes and two exclusive bus lanes that can accommodate light rail or trackless trams in the future.
- A bridge over Castle Creek along the new alignment.
- Increased transit capacity while decreasing transit time with continuous bus lanes from the roundabout to downtown.
- The highway across the 82-acre Marolt-Thomas properties covers 5.4 acres, and 2.5 acres are gained from the land bridge and decommissioned Highway 82 between the roundabout and Cemetery Lane.
- The existing Castle Creek Bridge remains in use as a local connection to the Cemetery Lane neighborhood and McLain Flats.
- Why was the Preferred Alternative chosen?
Increases future transit options like trackless trams or driverless buses.
Provides better emergency access and evacuation routes.
Reduces accident rates on the S-Curves.
Increases transit capacity while decreasing transit time with continuous bus lanes from the roundabout to downtown.
Eliminates the S-Curves so traffic will move more smoothly without the two, ninety-degree turns.
Creates direct access in and out of town due to a straighter alignment.
Creates an open space corridor connecting Marolt-Thomas Open Space to the Aspen Golf Course.
Creates a trail connection from the Marolt Bridge to the golf course that is uninterrupted by roadways.
Decreases traffic and congestion in the West End and Cemetery Lane neighborhoods.
- What challenges won’t the Preferred Alternative solve?
The Preferred Alternative is the approved option; it is not a silver bullet.
Travel times for general-use vehicles will improve by a couple of minutes, but will not solve the traffic or congestion problems.
The Preferred Alternative will increase travel times from Cemetery Lane to the hospital, Aspen schools, and Aspen Highlands.
The Preferred Alternative requires the existing Castle Creek Bridge to be repaired and eventually replaced to provide traffic access to Cemetery Lane and McLain Flats. It will also serve as a second exit from town.
- What elements of the Preferred Alternative have been implemented?
The Preferred Alternative was intended as a phased approach. Elements that have been completed as of 2022 include:
- Roundabout and a highway bridge replacement.
- Pedestrian overpasses over Maroon Creek and Castle Creek Roads.
- Harmony Road underpass and intersection improvements.
- Owl Creek Road realignment and new signals at Highway 82 at Buttermilk Mountain.
- Main Street bus lane addition.
- Conveyance of right-of-way. In 1996, Aspen voters approved an easement across Marolt-Thomas Open Space for two lanes and a light rail in exchange for Mills Ranch property as open space.
- Transit Management Program. Programs and policies encourage people to use the bus, bike, or walk.
The next phase of the Preferred Alternative is the Highway 82 realignment and a new Castle Creek Bridge.
Constraints of the S-Curves
The S-Curves have a long history. In 1891 when Pitkin County decided to build a bridge into town, officials chose the current location because the Colorado Midland Railroad was already coming into town on a trestle over Castle Creek, entering on what is now a pedestrian bridge. A large smelting operation, known as the Lixiviation Works (now the Holden-Marolt Museum), was in this location as well, inhibiting a direct link to Main Street. As the population and vehicle travel have grown in Aspen, the community has experienced a bottleneck at the S-Curves. This creates limitations including:
- Only 700-800 cars per hour can navigate through the S-Curves due to their shape and size.
- The current traffic alignment and travel patterns impact neighborhoods.
- Trackless trams, light rail, or other new technology can’t be implemented due to lack of space.
- Current backups out of town push vehicle traffic into the West End neighborhood causing safety issues and disruptions for residents.
Current Bridge Status
As mentioned above, The Castle Creek Bridge was built in 1961 with an estimated lifespan of 75 years - expiring in 2036. It was rated “fair” by CDOT in 2020 (52 out of 100) and will be reevaluated again soon. If the bridge falls below a fair rating (below 50), CDOT could put weight limits on vehicles crossing the bridge in order to protect the safety of our community.
The Path Forward - Two Choices
Because the Castle Creek Bridge’s lifespan only goes through 2036, we must start the 8-12 year bridge planning and implementation process now. There are currently two options for how to move forward.
1: Castle Creek Bridge Remains the Primary Entrance & Exit
- Requires more frequent repairs, and vehicle weight limits will impact commercial deliveries as the bridge further deteriorates.
- When more drastic repairs are needed, CDOT and FHWA will determine the best option to move forward to ensure the safety of the traveling public.
- Power Plant Road will need to be widened and realigned so that it can serve as a detour during the repair of the old bridge. This process can take 18 to 24 months.
- The rebuilt bridge will remain two lanes due to the existing bridge infrastructure such as the existing piers and foundation that holds up the bridge.
2: Build the Preferred Alternative
- CDOT and FHWA are looking to Aspen’s City Council for support of the Preferred Alternative so that the New Castle Creek Bridge can be constructed.
- The Record of Decision will undergo a standard reevaluation process.
- CDOT, FHWA, and the City of Aspen will engage the community around design details (ex. Pedestrian infrastructure and access), aesthetics, and open space planning (Land bridge design).
- Aspen voters will need to approve the use of Marolt-Thomas Open Space for exclusive bus lanes.
- The existing Castle Creek Bridge will be used while a new bridge is constructed.