Narrow tunnel in Colorado is so long it’s natural to be unsure about driving through
Published on Jun 15, 2025 at 5:49 AM (UTC+4)
by Claire Reid
Last updated on Jun 11, 2025 at 7:02 PM (UTC+4)
Edited by
Kate Bain
The Eisenhower-Johnson Tunnel in Colorado measures more than a mile-and-a-half long and is narrow enough to make even the most confident of drivers feel a little uneasy.
The tunnel was opened back in the 1970s and allows motorists to drive through the Rocky Mountains, rather than trying to tackle the tough terrain.
The tunnel is the result of an impressive feat of engineering, which involved blasting two bores under the Continental Divide in the Rocky Mountains.
Due to where it’s situated, the Eisenhower-Johnson Tunnel is one of the highest vehicular tunnels in the world.
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The idea to build such a tunnel in Colorado was first floated during the 1950s, decades before the Las Vegas Loop was ever dreamed of.
However, construction didn’t start until the late 1960s and took around five years to complete.
Since it opened up in 1973, more than 434 million vehicles have passed through the tunnel, with estimates suggesting around 32,260 vehicles use it every day.
To create the Eisenhower-Johnson Tunnel, a couple of bores were blasted and drilled to make room for lanes carrying both eastbound and westbound traffic.
The tunnels measure 1.6 miles (2.7 km) and have a 1.64 percent grade slope.
Height restrictions are in place, and the tunnels have a clearance of 13ft 11in (4.24 meters).
It’s also pretty narrow and has no shoulder, meaning that some folks might feel a little nervous about driving through.
However, it seems the fear may be misplaced.
To date, there have been no fatalities inside the Eisenhower-Johnson Tunnel, although accidents do, of course, happen.
Despite not having a shoulder, the tunnel can use a metering system, which uses traffic lights at the entrances, in an emergency situation.
This prevents more traffic from entering the tunnel, leaving the way clear for emergency vehicles.
In case of fire, there’s also a suspension system, which also includes sprinklers.
And, it’s kitted out with a forced air ventilation system that has giant fans that bring in fresh air and remove exhaust fumes.
There’s also an emergency power system that can provide back-up power, and closed-circuit television that allows the control room to monitor traffic flow, according to the Colorado Department of Transportation.
So, while a drive through the tunnel may feel a little off-putting, it’s actually very safe.
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Claire Reid is a journalist who hails from the UK but is now living in New Zealand. She began her career after graduating with a degree in Journalism from Liverpool John Moore’s University and has more than a decade of experience, writing for both local newspapers and national news sites. Claire covers a wide variety of topics, with a special focus on cars, technology, planes, cryptocurrency, and luxury.
