Eisenhower Tunnel, Clear Creek County
Inside the control room of the Eisenhower Tunnel, dozens of employees monitor more than thirty large screens, keeping watch on a throughway that, since its historic construction in 1973, has allowed hundreds of millions of cars to drive straight across the Continental Divide.
At 11,155 feet above sea level, the 1.7-mile tunnel is the highest of its kind in the world - something that drivers notice right away as they chug uphill on either side or crunch their brakes on the way down.
"It's a critical link from the east slope to the west slope, and has made huge differences for people in the way that they can access recreation and all that the mountains have to offer," says Mike Salamon, who has worked as a superintendent at the tunnel, sixty miles west of Denver, for 35 years.
The numbers prove it.
Since March 1973 through July 2012, exactly 304,794,917 vehicles have passed through the tunnel, and the rate is twice today what it was thirty years ago. On average, more than ten million cars pass through each year, or an average of 30,000 a day (sometimes it seems like they're all there at once). And although ski-season traffic gets the most attention because of traffic jams and bad weather, usage is usually highest in the summer.
Plans for a tunnel under the Continental Divide date back to the 1860s, but it wasn't until a century later, in 1968, that the technology and funding was created to make construction possible.
The $116.9 million effort, which began that year, employed thousands of people who worked 24 hours a day, six days a week. When it was done, people no longer had to take the twisting 9.5-mile route along U.S. 6 over the 11,992-foot-high Loveland Pass, but could use the new I-70 instead.
A project that calls for a 120-mile, high-speed transit system to be built on Interstate 70 between Jefferson County and the Eagle County Airport is certain to attract top thinkers - and the biggest dreamers - both foreign and domestic.
That includes Texas businessman Robert Pulliam, who doesn't believe high-speed rail will solve the traffic woes along the corridor.
A rail line is a key part of a Colorado Department of Transportation package of transportation solutions for I-70, which, if implemented, could cost more than $10 billion.
[T]he Glenwood Canyon project, completed in the 1970s, is a template for the type of original thinking that a tubular rail system could bring to the I-70 mountain corridor.