The Eisenhower Tunnel has seen more than 200,000,000 vehicles in its three decades of use |

The Eisenhower Tunnel has seen more than 200,000,000 vehicles in its three decades of use

EISENHOWER TUNNEL – Drivers passing over the Continental Divide on Interstate 70 Saturday likely never realized it – there were no cone-shaped party hats or noisemakers – but the Eisenhower Tunnel had a birthday.

Colorado Department of Transportation supervisors and workers quietly marked the 30th anniversary of the highest vehicular tunnel in the world. In its three decades, the tunnel has seen more than 200 million vehicles pass through its 1.7 mile bore.

“Thirty years ago, the Eisenhower Tunnel was an epic accomplishment – truly one of the most difficult projects in U.S. highway history,” tunnel supervisor Mike Salamon said in a press release Friday. “Along with I-70, this facility changed Western Colorado in many ways. It was definitely a benefit for the ski industry.”

Construction began on the tunnel on March 15, 1968 and was completed five years later. The bore initially funneled two-way traffic, until the second tunnel (known as the Edwin C. Johnson bore) was completed on December 23, 1979, and opened to eastbound traffic.

The westbound bore cost $116.9 million. The eastbound bore cost $144.9 million.

The tunnel eliminated the 9.5-mile drive over Loveland Pass, and its workers created a growth boom in the town of Silverthorne just a dozen miles below.

Traffic through the Eisenhower Tunnel quickly surprised planners.

“When the tunnel opened, traffic volumes exceeded expectations a lot faster than anyone anticipated,” Salamon said. “The early projections were for 14,000 vehicles a day by the year 2000. But what we actually average is about 28,000 to 30,000 vehicles a day. And over the last several years, traffic continues to increase about three or four percent a year.”

The 100 millionth car passed through the tunnel on June 29, 1992. The traffic volume mark took less than 10 years to double, and the 200 millionth car drove through the tunnel at 5:15 p.m. this past Monday.

The tunnel staff comprises 52 full-time employees keeping traffic moving day-in and day-out, year-round. The large staff is needed for additional responsibilities of “overheight management,” hazardous materials processing, emergency response, snow removal and tunnel washing.

The tunnel also is somewhat of its own city. It has its own fire department – each tunnel employee is sent to the Rocky Mountain Fire Academy, and a pump truck is stationed at the facility. Fires can be disastrous in tunnels, and to help with this, the CDOT crew also has a fleet of tow trucks and wreckers.

Power from Georgetown and Dillon feeds the tunnel’s electrical needs, but the complex has its own 500 kilowatt generator and a 125-volt bank of batteries, giving it a 24,000-volt potential.

A wastewater treatment plant processes about 72,000 gallons per day. There is also a 120,000 gallon water reservoir on the west side.

Although the footage probably won’t ever make “Must See TV,” the tunnel’s TV center collects images from 80 cameras monitoring the inside and the approaches.

A gargantuan ventilation system is employed to keep fresh air moving in and carbon monoxide from accumulating. Fans move more than half a million cubic feet of air in and out of the tunnel every minute.

And despite everything that could go wrong, the tunnel is one of the safest in transportation history.

“Safety always has been our top priority,” Salamon said. “I’m very proud to say, after 30 years and 200 million vehicles, we’ve never had a fatality in the Eisenhower. Plenty of car accidents, some vehicle fires and the like – but we’ve done a great job of handling the emergencies that have occurred. The success of the Eisenhower Tunnel stands as a tribute to the people who built it, the people who work here now and who have worked here in the past.”

Reid Williams can be reached at (970) 668-3998, ext. 237, or

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