PROJECT UPDATE: CDOT and Contractor Make Progress on US Highway 550 Molas Pass Improvements

September 21, 2017 - Southwestern Colorado/CDOT Region 5 - Motorists are advised of upcoming milling/asphalt operations

SW COLORADO –The Colorado Department of Transportation (CDOT) and contractor Rock & Company are pleased to announce that crews have completed the first and are nearing completion of the second of two under-highway downhill retaining walls known as crib walls on US Highway (US) 550 Molas Pass, just south of Silverton. The replacement crib walls are constructed by placing layers of reinforced wire mesh, geotextile fabric (for drainage), and special backfill materials.  

The most recent work included drilling and installing micro piles and rock reinforcement for a sound foundation and stabilization of the large rock slabs below the walls. Once the walls have been built back up to highway level, the road surface can be paved and new guardrail will be installed.  The project is on schedule for completion in mid-October.

TRAVEL IMPACTS:   Beginning Monday, September 25 crews will begin to remove the top layer of asphalt in the southbound lane, creating an uneven travel surface through the half mile project zone.  New asphalt will be placed in both the northbound and southbound lanes beginning on Monday, October 2.  While milling and asphalt operations are taking place, flagging crews will be managing traffic through the project zone during work hours of 7 a.m. to 6 p.m. with anticipated 20 minute delays.  After hours and on Sunday, portable traffic light signals will be in place, allowing alternating traffic at seven minute intervals.  

PROJECT OVERVIEW: CDOT and Rock & Company continue to work to improve the safety and integrity of US 550 Molas Pass, a high mountain pass just two miles south of Silverton in San Juan County.  There are two separate crib wall replacements, one at mile point (MP) 68.6 and one at MP 68.8.  Traffic is restricted to single-lane alternating traffic through the half-mile project zone as crews rebuild the supporting walls and install new guardrail.

STAY INFORMED: You can call the project hotline at (970)209-3332, email us at [email protected], or visit for more information.

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