DENVER — Thousands of drivers across the south metro will have to plan ahead and pack their patience (along with their lunch – or their skis) if traveling through the C-470 and Santa Fe interchange in Douglas County starting Friday night.
That’s because starting at 7 p.m. Friday, March 8, that interchange will be closed to all traffic — we’re talking northbound, southbound, eastbound, westbound — all of it. And it won’t just be closed overnight, no, no, no. The C-470/Santa Fe interchange will be closed 24/7 through next week. You read that right. No traffic will be allowed through that area through at least 5:30 a.m. Thursday, March 14.
It's all part of the Santa Fe bridge replacement project — which itself is part of the larger Santa Fe Corridor Project — that started in October of 2022 and won’t see its completion until the fall of 2025, according Douglas County leaders. Its goal? Make the bridge (US 85, or as it's more commonly known, Santa Fe Drive) that goes over C-470 wider so it can handle the increasing traffic along the corridor.
The full, five-day closure may seem like a traffic nightmare now (which it probably will be), but the improvements that will come from it are worth it, leaders said.
After it’s all done, the area will have bus stop enhancements, a new shared-use path for bicyclists and pedestrians on the east of Santa Fe Drive, a below-grade crossing for the C-470 and High Line Canal trails at Santa Fe, and a new pedestrian link from the Wolhurst community to the C-470 Trail. New auxiliary lanes, asphalt paving, raised medians, new curb and gutter, and a new closed storm sewer system with water quality ponds are also coming as part of the project.
THE ROAD CLOSURE: WHAT’S THAT GOING TO LOOK LIKE AND HOW CAN I GET AROUND IT?
Your commute is going to get a little hectic for several days and while this may seem a little confusing, project managers in charge of the demolition told Denver7 traffic expert Jayson Luber they thought of “every single way we could possibly do this” while keeping driver safety top of mind. Ready?
For those traveling along C-470:
Eastbound and westbound C-470 will be completely closed at Santa Fe, but traffic will move using the off- and on-ramps as the detour. Drivers would exit at Santa Fe, go past the light that will be set to green, continue to the on-ramp and then continue on C-470.
“So you'll be able to go up the off-ramp, go through the signal without stopping and then use the on-ramp to get back on,” said Mike McNish, the area manager with Kraemer North America, the contractor for this project.
For those traveling along Santa Fe Drive:
Santa Fe will be closed on the north side at County Line Road and on the south side at Blakeland Dr. The flyover ramp from southbound Santa Fe to go east on C-470 will remain open, McNish explained. The Santa Fe detour is going to take drivers east to Lucent Blvd. from either County Line Rd. on the north, or Town Center Dr., on the south.
Here's what the detour looks like for those going north on Santa Fe:
And here’s what it looks like for those traveling south on Santa Fe:
McNish suggested using 6th Ave. well north of this project as an alternate route.
Luber, however, said local roads will carry some of the detoured traffic and it will be difficult to maneuver through this each day but especially on Friday evening and during the Monday and Tuesday commutes, both in the morning and evening.
McNish said they anticipate delays of up to 20 minutes in the area, but when pressed by Luber about potential hour-long delays over the course of the closure, McNish said there was no specific detour route other than those on- and off-ramps, and encouraged drivers who usually take the C-470/Santa Fe interchange “to use some of the other regional roads that are that are available to them to avoid using and getting into this area altogether.”
If the work is completed ahead of schedule — and weather-permitting — crews will work hard to make sure the roadway is reopened earlier than expected, he said.
WHY NOT JUST CLOSE THE INTERCHANGE OVERNIGHT TO AVOID THIS TRAFFIC NIGHTMARE?
Wouldn’t that be nice?! Unfortunately, that’s not going to be possible this time around. And you can thank engineers in the late 60s for that.
“A lot of the bridges around town are made up of precast beams that you can systematically take one girder out at a time, and the rest of the structure could be completely stable,” said Mike McNish, area manager with Kraemer North America, the contractor for this project.
But the structure that holds that section of Santa Fe Drive together, built in 1968, is made up of a continuous span of beams instead of individual, precast beams, he said.
“This type of structure, once you start demolishing it and taking pieces out of it, the rest of the structure is not as structurally stable anymore. Bottom line, it’s 100% about public safety,” McNish added.
Once demolition begins, it needs to continue as the structure will not be stable any longer. Hence the reason for the long closure, he told Luber this week.
WANT SOME FUN FACTS ABOUT THE PROJECT?
The folks over at Kraemer North America will bring about 300 truckloads of dirt that will put about a five-feet buffer over C-470 so that when the concrete from the Santa Fe bridge falls beneath, the roadway underneath won’t be damaged.
In all, crews will be removing over 540,000 pounds of steel rebar and there will be enough concrete debris that comes from the bridge removal to cover the football field at Empower Field at Mile High, twice.
Editor's note on Wednesday, March 6: The closure was originally scheduled to begin Thursday evening but is being pushed back a day due to weather, Douglas County leaders told Denver7 Traffic Expert Jayson Luber.
