IDAHO SPRINGS, Colo. (CBS4)– The Interstate 70 Mountain Express Lane opens on Saturday to drivers heading east from Empire to Idaho Springs. Tolls will be waived during the testing phase of the lane but drivers are encouraged to get an Express Toll pass.

The I-70 Express Lane operates for 13 miles between the twin Veterans Memorial Tunnels near Idaho Springs and the Empire exit. The lane allows eastbound traffic to use a newly built “shoulder lane” during peak travel periods.

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The toll on the 13-mile stretch will vary based on how many cars are slowing down traffic, starting at $3 and increasing all the way to $30.

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“It can range anywhere from $3 to $5 to $10 it’s all about how we use the prices as a way of maintaining reliable travel speeds in the corridor and when they do that you should expect you’ll have 30 minutes time savings when you travel in that lane,” said Colorado Department of Transportation Communications Director Amy Ford.

Some other states have flexible-toll express lanes, but Colorado’s toll idea is unusual because it would apply mostly to winter recreational travelers, not workday commuters. The ski lane would be open only 73 days a year — weekends and Monday holidays.

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When not in use the lane is used as a shoulder.

(credit: CBS)

(credit: CBS)