US Highway 36 Intersection Improvement Project

Project Description

The US 36 (North Foothills Hwy.) Intersection Improvement Project is a partnership project between CDOT, Boulder County, and the Town of Lyons to improve intersection safety on US 36 between Lefthand Canyon Dr. and Apple Valley Rd. west of Lyons. In addition to repaving a section of US 36, the project will include striping changes and shoulder widening to increase space for bicyclists and to more clearly indicate conflict zones at intersections. The project is being funded by CDOT, Boulder County, and a Safer Main Streets grant.

Project Funding

• $8.2M from CDOT
• $240,000 grant from the CDOT Safer Main Streets Initiative
• $60,000 from Boulder County

Project Schedule

• Design Complete – Fall 2022
• Advertise for Construction – Winter 2022-23
• Begin Construction – Spring 2023
• Complete Construction – Summer 2023

Changes by Location

US 36 and Lefthand Canyon Drive

• Striping modifications, related signage, and minor shouldering widening on the east side of US 36 to increase the shoulder width and highlight the bike lanes through the intersection at conflict points with turning motor vehicles
• Creation of a shared SB right turn lane and bicycle through lane
• Removal of pork chop islands and replacement with asphalt

US 36 and Nelson Road

• Striping modifications, related signage, and shoulder widening on the east side of US 36 to separate the NB right turn lane and the through the bicycle lane

US 36 and St. Vrain Road

• Striping modifications and signage to highlight the location of bicyclists travelling northbound through the intersection
• Creation of two stage WB to SB left turn movement for motor vehicles

US 36 and Hygiene Road

• Striping modifications and signage to highlight the location of bicyclists in the intersection
• Creation of a southbound shoulder where none currently exists
• Elimination of unnecessary SB bus acceleration lane
• Creation of two stage WB to SB left turn movement for motor vehicles

US 36 and State Highway 66

• Striping modifications to preserve the bike lanes through the intersections and highlight the locations of bicyclists as they cross the EB to SB and NB to EB right turn slip lanes
• Creation of a NB “bike box” to improve visibility of left turning NB to WB bicyclists at the intersection

US 36: State Highway 66 to 2nd Avenue

• Striping modifications to widen the shoulders (from 2’ to 4-5’) and create more space for bicyclists
• Skip striping to highlight the location of bicyclists at intersections and driveways
• Narrow travel lanes from 12’ to 11’ in both directions to reduce motor vehicle speeds and create more room for additional shoulder and bike lane width

US 36: 5th Avenue to Apple Valley Road

• Striping modifications to widen the shoulders/bike lanes and create more space for bicyclists, including the use of skipped striping at intersections to designate a space for bicyclists

CDOT Plans

• View the CDOT plans

Project Contacts

Boulder County Community Planning and Permitting
Alex Hyde-Wright, Principal Transportation Planner, ahyde-wright@bouldercounty.gov , 303-441-4910
Alexandra Phillips, Bike Planner, aphillips@bouldercounty.gov, 303-441-4520