South End
The design team presented two design to the public in May 2026. Feedback from the public indicated the best connectivity for all users would be to provide both alternatives.
The new underpass option flows better, does not require crossing US 36 and offers a more direct route for cyclists traveling southbound.
The option running along Old Broadway is more direct and flows better for those heading northbound toward Lyons.
How much more will it cost to construct both options?
As of now, neither option is funded. The county is actively pursuing grant funds for construction. The design team is proceeding with designing both, but the priority will be to construct the option that runs along Old Broadway and add the underpass if funds become available.
The design option that runs along Old Broadway is the cheaper of the two to construct. Construction of the underpass option does add about $2 million which includes the additional bikeway leading to and from the new underpass.
Why not use the existing underpass between Old Broadway and the westside of US 36?
The existing underpass is in poor condition, has poor drainage and is undersized to accommodate the bikeway and would result in poor sightlines on the north side of the underpass. Using the existing underpass would have to be replaced so there are no cost savings by using it.
Connecting the existing underpass would require a section of bikeway to be constructed in wetlands between the existing underpass and the City of Boulder.
Neva Road
Why was the overpass option chosen?
Feedback from the public highlighted that an at-grade crossing design would not meet the safety goals of the project. The at-grade bikeway crossing would not be safe for cyclists and could result in rear end collisions of vehicles if one driver stopped before crossing if other drivers did not stop.
The overpass option eliminates the possibility of motorized vehicles and cyclist crashes at this location and requires less barrier than the at-grade crossing.
The design for Neva Road also includes road safety improvements of a left turn lane for vehicles turning onto Neva Road and an improved right turn lane
Lefthand Canyon Drive
Why was the at-grade crossing to Lefthand Canyon Drive chosen?
- Public feedback and technical input from the partners and the bikeway design engineers revealed several formidable issues with using the existing bridge over Left Hand Creek as an underpass.
- The creek and riparian area along the creek are heavily used by wildlife.
- The bikeway would be flooded in high water conditions with no suitable detour.
- Limited CDOT owned land or other public lands to connect the underpass to Lefthand Canyon Drive.
- The underpass option would require a mid-block at-grade crossing on Lefthand Canyon Drive for cyclists biking up the canyon.
- The at-grade crossing would allow for the most cyclists movements to and from the bikeway to Lefthand Canyon Drive and Plateau Road.
Will there be a signal installed?
CDOT requires a signal warrant study for any type of signal (full signal, HAWK or other type) to determine if and what type of signal is warranted. The county has submitted a signal warrant study and is working with CDOT on the outcome.
Intersection of US 36 and CO 66
Why was there only one design option for the US 36/CO 66 intersection shown to the public when other focus areas had at least two design options presented to the public?
The bikeway design engineers explored the bikeway crossing under the existing bridge but there is not enough CDOT or other publicly owned land to do this. To get the bikeway from the road to down under the bridge, the bikeway needs adequate distance to remain at a reasonable grade (under 5%). To achieve this, the design team considered multiple alignments including crossing on the south side of the creek and on the north side. None of the alignments could achieve reasonable grades without needing significant easements from private property owners. Due to these challenges, an at-grade crossing that includes numerous safety improvements was selected. Improvements include refuge islands with raised crossings, more visible pavement markings, and revised right turn lane from CO 66 to US 36 that would slow down drivers, all these additions would improve safety and connectivity for bikeway users in all directions.
What are the criteria used to select the design options?
Comments collected at the May 2026 open house, meetings with cycling safety advocates, comments from a 13-member community advisory committee and an online survey with more than 800 respondents was used to help guide the selection.
Input from our project partners at CDOT, City of Boulder Open Space and Mountain Parks and Transportation and Mobility, County Parks and Open Space and Public Works, Town of Lyons helped guide the selection.
Other considerations and constraints were the amount of CDOT owned land or other public lands, avoiding or minimizing impacts to rare plants, wetlands, and wildlife, not decreasing shoulders and additional design features that would increase safety for motorists on the road.
The bikeway design engineers followed the Manual on Uniform Traffic Control Devices, a book created by the Federal Highway Administration that is the law of national standards and the Public Right-of-Way accessibility Guidelines, which are federal requirements, The design team also incorporated Boulder County’s Multimodal Standards and best practices in recent bikeway construction in the west.
How will the bikeway accommodate both recreational riders and experienced/high-speed cyclists?
The bikeway is designed to be 12-foot wide with a wide soft surface shoulder. The existing US 36 bikeway which is also 12-foot wide.
Public feedback was clear that frequent stops or sharp turns on the bikeway would be intimidating for the interested but concerned riders and would dissuade the confident riders from using the bikeway. The design team has only included curves, yields or stops where absolutely necessary and has made any needed turns as wide as possible.
Will wildlife underpasses or crossings be included as part of the project?
The bikeway design team is coordinating Parks and Open Space on the wildlife crossing project.
How will wetlands, rare plants, and sensitive habitats be protected?
The design options were carefully planned to avoid wetlands, sensitive habitats and rare plants. In the few small areas where there could be impacts, mitigation measures will take place.
Will cyclists still be able to use the road shoulders when the bikeway is built?
While the bikeway is being designed to encourage use by all types of cyclists, cyclists will not be legally prohibited from riding on the US 36/North Foothills shoulder.
In a 2024 bikeway survey, over 75% of respondents who currently ride on the shoulder said they would ride on the bikeway once it is built. In the same survey, 93% of those that do not currently ride on the shoulder reported that they would ride on the bikeway once it is built.
