Integrated weather monitoring and variable speed limit system deployed on I-70 in Colorado


The Colorado Department of Transportation (CDOT) will begin work on a major project on Interstate 70 in October, which is intended to improve safety on a section of the highway that has been identified as particularly hazardous in inclement weather due to poor roadway conditions.

The year-long project involves the installation of interconnected weather and road sensors, cameras, speed-detection devices and variable speed limit signs at 17 locations on the I-70 Glenwood Canyon corridor, including the Hanging Lake Tunnel (HLT) area, which is particularly susceptible to the impact of severe weather conditions. Work will extend about 14 miles (22.5km) on eastbound I-70 and about 15 miles (24.1km) on westbound I-70, including the HLT area. CDOT’s work will include:

• Installing three weather stations for live monitoring and reporting of weather conditions;

• Installing 73 standard static signs;

• Installing 17 new dual, variable speed limit signs;

• Replacing five single variable speed limit signs;

• Removing 38 existing static signs;

• Installing nine closed-circuit cameras for live monitoring and viewing of roadway conditions; and adding other surface and subsurface conduit, and related improvements to guide the display of the variable speed limits.

The Glenwood Canyon section of I-70 experiences a wide range of weather types throughout the year, causing unsafe driving conditions for those that do not take proper precautions. Based on a recent safety assessment by CDOT, this area sees a high number of crashes involving fixed objects, especially during inclement weather.

The new technology being deployed will:

• Give drivers advance warning, and generate a safer traffic flow to decrease accidents in the canyon;

• Increase the standard speed limit during good conditions to 60mph (100km/h) for passenger vehicles and 50mph (80km/h) for heavy vehicles, in most of the affected areas;

• Lower the speed limit to assist with incident management, conditions created by inclement weather, and maintenance and construction.

Elsewhere in the state, CDOT crews have completed a five-month project on the US Highway 160 Wolf Creek Pass, which involved the installation of 18 miles (29km) of fiber optic cable. The project will optimize digital controls within the Wolf Creek Tunnel, while Colorado communities will gain high-speed telecommunications.

Other work on the US$4.5m project included: road surface milling, repaving, and pavement re-striping along the 16-mile long (25.7km) stretch of the US 160 mountain corridor. Crews also completed work on electric message and speed signs in Monte Vista, Alamosa and La Veta Pass.

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Tom has edited Traffic Technology International (TTi) magazine and its Traffic Technology Today website since May 2014. During his time at the title, he has interviewed some of the top transportation chiefs at public agencies around the world as well as CEOs of leading multinationals and ground-breaking start-ups. Tom's earlier career saw him working on some the UK's leading consumer magazine titles. He has a law degree from the London School of Economics (LSE).