New Castle Creek Bridge

Aspen's Transportation Future NCCB Logo

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.  

Get Up to Speed 

This 5-minute video runs through the history of the Entrance to Aspen to the present day. Learn more about the journey Aspen has taken through the lifetime of this project and where we're headed. To keep informed about the project, subscribe to receive email updates.

Questions? Email us.Click here to watch a short video about the New Castle Creek Bridge project. Opens in new window

Click here for more information about the history of the Entrance to Aspen
Click here for more information about the Preferred Alternative
Click here for more information about upcoming events

Current Bridge Status

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 2022 (50.3 out of 100). 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.

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.

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 are looking to Aspen’s City Council for support of the Preferred Alternative so that the New Castle Creek Bridge can be constructed. CDOT and FHWA will determine the best option to move forward to ensure the safety
  • Power Plant Road will need to be widened and realigned so that it can serve as a detour during extensive repairs or reconstruction 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 piers and foundation that hold 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 (ex., land bridge design).
  • Voters approved the use of a two-lane parkway and light rail. Another vote is needed to allow bus lanes until funding is available for light rail.
  • The existing Castle Creek Bridge will be used while a new bridge is constructed and then later reconstructed as an additional entrance/exit from downtown.