Quick summary: Starting November 1 and running through February, bright mornings can push eastbound I-70 traffic at Floyd Hill onto a detour from sunrise to 8:30 a.m. CDOT wants drivers to hear this clearly: it is a detour, not a closure. Traffic keeps moving, it just leaves the highway at the bottom of Floyd Hill and gets back on at Beaver Brook. The first taste comes this week: CDOT says crews will run a preparatory traffic hold around 7 a.m. on Wednesday, October 21.
What is happening
CDOT announced this week that the seasonal sun glare safety detours are returning to eastbound I-70 at Floyd Hill, roughly Mile Points 244 to 248, east of Idaho Springs. The season starts November 1 and runs through February, in a morning window from sunrise to 8:30 a.m.
This is not an every morning thing. Whether a detour runs is decided daily, case by case, by Colorado State Patrol and CDOT crews stationed near Floyd Hill, based on what that morning actually looks like. Some mornings you will sail through. Some mornings you will be routed off the highway.
Eastbound drivers get one early rehearsal. CDOT says crews will run a preparatory traffic hold at approximately 7 a.m. on Wednesday, October 21, ahead of the season. If you drive east on Wednesday morning, give yourself extra room.
The detour, step by step
When a detour is in effect, eastbound traffic leaves I-70 at the bottom of Floyd Hill. From there you have two ways east: US 6 through Clear Creek Canyon, or the eastbound frontage road, US 40. Both routes rejoin I-70 at Beaver Brook, Exit 248.
Plan on it costing you time. CDOT says to prepare for delays of up to an hour when the detours run. If your morning has a hard deadline on the other side, build the hour in before you need it.
And because this trips people up every year: this used to be called a sun glare closure. It is not one. Nobody is stopping traffic wholesale. You are being rerouted around the worst of the glare, and then you are back on the highway.
Why this stretch of highway
The morning sun sits low in the east, which puts it straight into eastbound windshields on this stretch. Wet pavement makes it far worse. Rain, melting snow, and even the liquid pre-treatment crews put down ahead of storms all amplify the glare. Floyd Hill then adds steep grades and sharp turns that cut your sight distance, and sudden hazards, like wildlife crossing the highway, do not wait for you to see them.
This has been a known problem spot for a long time. In the 1990s, before there was a protocol, state troopers stationed near Floyd Hill manually held or slowed traffic when the glare spiked morning crashes. By the early 2000s, with commuter and freight traffic growing, CDOT and CSP made it an official seasonal detour window. It has been part of winter on this corridor ever since.
What to do with this
From November through February, check conditions before any early eastbound drive. COtrip.org and the COtrip Planner app carry the morning alerts, and since the detour call is made that same morning, a plan you made the night before is not enough. If a detour is running and your schedule is flexible, waiting until after the 8:30 a.m. window closes is a legitimate move.
Two groups can relax. This only affects eastbound traffic, and only in the early morning. Westbound drives and afternoon trips home are not part of it.
New I-70 Things gear is coming this fall. Join the email list at i70things.com and you will hear about the drop first, plus the road posts that actually matter this winter.
Photo: CDOT. Sun glare on eastbound I-70 near Floyd Hill, photographed in 2025. This is the glare that triggers the seasonal morning detours.
Sources: CDOT news release, "Sun glare safety detours return to eastbound I-70 at Floyd Hill," codot.gov, checked October 19, 2026. Live road status checked on COtrip.org and the National Weather Service forecast checked Tuesday morning, October 20, 2026.