Are We There Yet?
by Claudia Lamb

What does it look like when 50,000 vehicles squeeze through a tunnel under the continental divide? Imagine a traffic jam 70 miles long.

The main artery for East/West travel through Colorado is I-70, 450 miles of Interstate highway stretching from Utah to Kansas. At the 1/2 way point is the Eisenhower/Johnson Memorial Tunnel, a marvel of engineering which took 11 years to complete. Situated at 11, 112 feet above sea level, it is the highest vehicular tunnel in the world. Its twin 2 lane bores are 1.7 miles long.

Over 50,100 vehicles traveled through the Eisenhower tunnel on Sunday August 5, 2001. It was the highest 24 hour traffic count in its 27 year history. It capped a record breaking weekend, where 140,367 vehicles passed through the tunnel from Friday to Sunday - the highest combined 3 day weekend count in history.

So why all the traffic? It's wasn't even a holiday.

Long holiday weekends tend to see steady, heavy volume with people spreading out their travel time. They'll leave on Thursday night or return Sunday afternoon to avoid traffic.

But, the first weekend of August is in many ways the last full weekend of summer for us in Colorado. School is 10 days away. Lots of folks are squeezing in one last (or sometimes first) homework-free family trip. Others are getting out of the extreme heat in the Denver Metro area. Most head for the mountains and use I-70 to get there.

Imagine hundreds of thousands of people with the same great idea at the same time. Imagine motorcycles, minivans and motorhomes; semi trucks carrying cargo, pick-up trucks towing trailers and SUV's with bikes and kayaks strapped on top. Imagine them all coming home. At the same time.

Between noon and 6 pm almost 25,000 vehicles passed through the Eisenhower tunnel; 15,668 of them used the Eastbound bore, with volume surpassing the estimated capacity of 2,500 vehicles per hour. New hourly tunnel count records were set at 3 pm and 4 pm, with the 5th and 7th highest single hour counts, respectively, in tunnel history. There were no major incidents and traffic flowed smoothly, but slowly. Very slowly. It was literally "bumper-to-bumper" from Silverthorne to Denver.

When people are sitting in a 70 mile long traffic jam they want answers.

At CDOT's Traffic Operations Center, in Lakewood, we use phones, faxes, the Web, Variable Message Signs and Highway Advisory Radios to provide answers to the traveling public. We can tell you about current road conditions, chain restrictions, construction projects and closed roads, not to mention huge traffic jams in the mountains.

We monitor the flow of traffic and weather conditions along the I-70 corridor using cameras placed along the highway, with camera feeds from Idaho Springs, Empire, Georgetown, the East and West faces at the Eisenhower Tunnel, Silverthorne, Copper Mountain and Glenwood Canyon. We keep track of volume on the highway with the hourly tunnel counts. We keep in direct contact with the Colorado State Patrol to monitor incidents.

Twenty-four hours a day, seven days a week, we combine these information sources to keep the public informed about highways in Colorado. We determine when messages advising of delays should appear on the overhead Variable Message Signs. We record and run audio messages on our Highway Advisory Radios. We update our recorded telephone Information Hotline with the latest travel conditions. We post current information on our website. We answer telephone calls from the traveling public. In addition, we advise the media of conditions on the highway to further the flow of information.

On August 5th, 2001 more vehicles used the Eisenhower Tunnel than on any other day. Volume at the Tunnel didn't drop below 1,000 vehicles per hour until 11 pm. The average drive from Silverthorne to Denver took more than 3 hours. Motorists may not have been happy sitting in a record breaking traffic jam, but at least they knew why.

Claudia Lamb is a Public Information Officer at the Traffic Operations Center. She has a background in news and broadcast traffic reports.