Mid-summer heat has turned the U.S. 36 Bikeway near Boulder into a surprise roller coaster, with concrete swelling into sharp ripples that can pop up almost overnight. Riders are getting little warning before they hit the up-and-down heaves, so local crews are racing to grind out and repour damaged panels while officials throw up temporary cones and signs as fast as conditions change. Cyclists and e-bike riders are being urged to ease off the throttle on descents and pay close attention to the warnings.
Where It’s Happening And What Officials Say
According to Denver7, City of Boulder officials say high afternoon temperatures have caused sections of the US 36 Bikeway to heave and buckle, and that warning signs and cones are in place while crews work. The city is asking anyone who spots new heaves to call non-emergency dispatch at 303-441-3333, and notes that repairs will be made "as conditions allow." Bike crashes have already been reported after riders struck some of the raised panels, the city added.
Why Pavement Buckles In Heat
Concrete slabs expand as they warm. If joints, spacers or the supporting base do not give them enough room, the resulting compressive forces can shove panels upward and create buckles or "blowups," engineers explain. Federal guidance and technical studies, including the FHWA-backed guide from InTrans, identify thermal expansion, base-support failures and poor drainage as common triggers. Those resources recommend design allowances, proper jointing and timely repairs to manage thermal deformation before it turns into a safety hazard.
Rider Safety And Local Response
Local maintenance crews have been cutting out unstable slabs and repouring concrete where they can safely work, and warning signs are being shifted or beefed up as trouble spots move, Denver7 reports. Regular users of the corridor are being asked to slow down during the afternoon heat, especially on the steep descent into Boulder, and to call the city’s non-emergency number to report new hazards. Officials caution that some temporary fixes may only last until the next hot spell, so riders should treat the path with extra respect when temperatures spike.
Heat, Infrastructure And What Comes Next
The National Weather Service has been calling for a prolonged hot pattern along the I-25 corridor, with daytime highs in the 90s that load extra thermal stress onto roads, bridges and trails. Research on climate impacts and transportation infrastructure notes that more frequent and intense heat waves will increase maintenance needs for pavements and pressure agencies to rethink materials and design standards, as highlighted in one review of climate impacts on transportation systems. CBS News Colorado has shown video of the buckled concrete and repair crews working along the US 36 Bikeway as the hot streak drags on.
