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April 3, 2018

Contact: Andrew Barth, Boulder County Transportation, 303-441-1032

Cycling restrictions in Fourmile Canyon begins 4/3/2018

No daytime, weekday recreational cycling due to safety concerns during construction


Boulder County, Colo. – Beginning at 8 a.m. on Wednesday, April 4, cycling on Fourmile Canyon Drive will not be allowed between Boulder Canyon Drive/SH 119 and the Sunset townsite and also along Gold Run Road from Salina Junction to just south of Gold Hill. Cycling restriction will be enforced during project working hours, which are 8 a.m. to 4:30 p.m., Monday through Friday. Restrictions will be enforced until officials deem the area once again safe for cycling.

Canyon residents who rely on cycling for commuting and errands will again be exempted from restrictions. Residents will need to carry photo identification that proves they live in the canyon. They can also obtain a cycling pass by contacting Andrew Barth at or by calling 303-441-1032. The passes are good for individual use and are non-transferrable.

The restriction will be enforced by the Boulder County Sheriff’s Office. Anyone violating the restriction could be subject to citation by law enforcement.

The restriction is being enacted due to safety concerns stemming from the extremely high volume of construction activity taking place in the canyon. There are currently three major flood recovery projects taking place and there is one more that is yet to start – lower Fourmile Permanent Flood recovery anticipated to start later this summer. Each project requires a heavy volume of large truck traffic that heads up and down the road during working hours. Due to the narrow, curvy nature of the canyon’s roads, it has become increasingly difficult to safely share the road between cars, trucks, and cyclists. Trucks hauling materials take up nearly the entire lane, which leaves little room for cars, let along cars and cyclists.

Boulder County Transportation thanks everyone for abiding by the restrictions. We understand how important and popular Fourmile Canyon is for cycling and we will do our best to lift the restrictions as soon as possible.

Courtesy is Contagious – Share the Road

Boulder County is asking for patience and understanding while the restriction is in place. Canyon roads under repair will see a heavy volume of large trucks and machinery, which will make travel difficult for all modes. The lengths and widths of the trucks used to haul materials can force them into the opposite lane in areas with tight curves and where the road has been narrowed due to a washed out shoulder. In addition, fully-loaded trucks may not be able to stop quickly to avoid cyclists moving downhill. Boulder County would like to avoid any accident that could cause any bodily injury to cyclists or motorists.

Sunshine, Lefthand, and other arterial canyon roads that are open to all modes are likely to see a large increase in cycling activity during the work in other canyons. The county is asking all drivers and cyclists to please be aware of their surroundings and other roadway users at all times, and remember to share the road. Motorists are asked to provide cyclists with three-feet of space, if safely possible, when passing, and cyclists are reminded that they are only permitted to ride two-abreast as long as they are not interfering with motorists. During all flood recovery work, Boulder County is asking that all cyclists ride single-file when using mountain roads west of US 36. Motorists are allowed to cross a double-yellow lane-dividing line when passing cyclists, but please use caution doing so when entering curves as an approaching car may not be seen until the two vehicles are too close to avoid collision.

While Boulder County Transportation strives to complete all projects on-time, work is weather dependent and there may be delays due to rain or other unfavorable working conditions.

For more information on the work, visit the project website or contact Andrew Barth, Transportation Department communications specialist, at or call 303-441-1032.

All current Boulder County Transportation roadway project information, including regular maintenance and flood-recovery activity, can be found at – –