Update: All lanes of southbound Interstate 25 between Park Avenue and 20th Street are now open after the four right lanes were closed for more than seven hours Wednesday morning.

Traffic began flowing southbound around 11:40 a.m. after crews were able to hoist a shuttle buggy back onto its wheels and haul it off the interstate. A shuttle buggy is used to transfer hot mixed asphalt, which weighs roughly 80,000 pounds.

The buggy fell off a flatbed truck around 4:30 a.m. in a coned-off work zone as contract crews were removing the equipment following overnight resurfacing work on I-25. 

CDOT said the buggy laid on its side until approximately 10:30 a.m., before crews were able to flip it onto its wheels.

The four right lanes on Interstate 25 southbound between Exit 213: Park Avenue and Exit 212C: 20th Street in Denver at mile point 212.5 are closed due to an overturned shuttle buggy.

The only open lane currently is the far left lane, and backups are reported to U.S. 36. 

CDOT urges drivers to use the HOV/Express lane if possible to avoid the wreckage as maintenance crews assess the crash and position tow vehicles to roll the buggy back onto it’s wheels. The express lanes are jammed up as well. 

Backups can be expected all the way to 88th Avenue in Thornton.

Commute times from Thornton to downtown Denver are estimated to be 90 minutes. Travelers reported backups gridlocked traffic on U.S. 36, including the express lanes. 

The incident took place around 4 a.m. Wednesday morning as a Colorado Department of Transportation contractor was finishing work for the night, a spokesperson from CDOT said Wednesday. As they were lifting the buggy, which weighs about 80,000 pounds, onto a flatbed truck to take it away for the night, it fell off the platform.

Maintenance crews from CDOT have since responded to the scene, and are currently working on getting the buggy upright and off the roadway, the spokesperson said. Even after removing the vehicle, it will take a while longer for crews to clean up the work zone itself before reopening the roadway for vehicle travel.

The spokesperson anticipated that the scene will remain the same through Wednesday morning, but could not give a more specific timeline for how long it will take to fully reopen the interstate.