DILLON, Colo. -- The walls inside the Eisenhower Tunnel are brighter after CDOT worked to wash the dirt off the walls and ceilings from the winter season.
Denver7 got a look at how CDOT crews get the job done. The walls stretch nearly two miles long. A team scrubs the filthy walls using a tanker and a rotary brush.
John Wheatley with CDOT cleaned the tunnel before.
"I love it. It's fantastic. It's like a big video game," Wheatley said. "Trying to put that arm where you want it, it's just a huge challenge."
The challenge is avoiding hitting the fluorescent lights and cameras inside the tunnel. Not to mention, the traffic as one lane gets blocked off while crews clean.
The walls and the ceilings look completely different once the crew comes by.
"Many can see it makes it brighter in the tunnel, which creates a safety level," Wheatley said.
That's not the only reason why they have to keep it clean.
"The corrosive nature of some of the deicers and some of the road grime, we want to get that off the walls as quickly as we can before it actually has a chance to soak in and possibly get to some of the steel," Wheatley said.
The dirty water that pours off the walls and onto the ground gets treated.
"It goes into our water waste water plant where it's filtered and treated before it gets released," Wheatley said.
The tunnel gets cleaned before Memorial Day Weekend and Labor Day Weekend.