I-70 Exit 26 Interchange Project Restarts Monday, February 24th

February 21, 2014 - Northwestern Colorado/CDOT Region 3 - Traffic switch to the Diverging Diamond configuration scheduled for Thursday night.

MEDIA RELEASE: The Colorado Department of Transportation’s (CDOT) Diverging Diamond Interchange project (DDI) at Exit 26 on I-70 is restarting after a 9-1/2 week closure due to weather and poor working conditions on the site.

The project, which was shut down by CDOT last December 18th after several weeks of harsh winter  weather, will be restarted again on Monday, February 24th.  The contractor, Lawson Construction, will be mobilizing and beginning  the work  on Monday,  Work will first concentrate on preparing the new driving lanes for the DDI configuration, with the traffic switch over to the new configuration scheduled forThursday evening, February 26th.  Work needed to put traffic into the new DDI configuration includes placement of the concrete barrier between lanes, pavement striping, signage, and adjustment of the new traffic signals.

CDOT Resident Engineer Rob Beck said that the decision to shut down the project last December boiled down to safety of the motorists going through the intersection.  “We didn’t want to put the DDI into its final configuration last December without the striping and safety elements in place” Rob said.  He added "We anticipate that the DDI will be well received and will improve the driving experience and safety, but a DDI isn't the sort of thing you can partially implement.  We wanted it to be right when we introduce the new configuration to the public.”

After traffic is in the new DDI configuration there will be a few more weeks of work left to place off-traffic improvements such as site grading, landscaping and sidewalks.  Weather permitting the project should be completed in March.

TRAFFIC IMPACTS: Traffic will we switched over to the DDI configuration on Thursday night, February 26th . Through traffic will be limited to one lane of traffic in each direction until the project is complete. Some lane and shoulder closures will be required for work on the remaining off-traffic improvements such as landscaping, sidewalks and revegetation.  The speed limit will remain at 35 mph.

BACKGROUND: The diverging diamond is a new and innovative interchange design that improves efficiency by reducing wait time for left-hand turn movements. The I-70 DDI eliminates traditional left-hand turns by crossing lanes and shifting drivers to the left side of the road through the interchange. This gives drivers direct access to a left-hand ramp to access the interstate without waiting at a traffic signal. The lanes then shift drivers back to the right side.

Diverging Diamond Interchanges can carry much more traffic than conventional  interchanges, and the capacity for left-turn movements is twice that of a conventional interchange. Safety has been shown to increase at interchanges and intersections built as diverging diamonds. The amount of crashes are reduced, as are the severity of crashes. The accidents that do occur are at angles that eliminate the dangerous “T-bone” that can happen at a traditional signalized intersection.

The total cost of the I-70 DDI is $4 million,* whereas other alternatives for interchange reconstruction are between $10 and $15 million. Minimal right-of-way acquisition is required for this type of interchange.

The City also had an adjacent project underway at 22 Road (see below); This project has been completed.

PROJECT INFORMATION:  Additional information on these two projects is available via the following: 

*CDOT’s DDI will be paid for, in part, with FASTER funds. Funding Advancements for Surface Treatment and Economic Recovery was established by the Colorado General assembly via Senate Bill 09-108 (www.coloradodot.info/projects/faster) to fund the repair or replacement of Colorado’s poor-rated bridges and make safety improvements to Colorado’s key corridors.