Overnight construction will close sections of Interstate 70 near Idaho Springs and Hidden Valley on Oct. 18, 19 and 20 as crews continue building a bridge for the Floyd Hill project. Eastbound I-70 is scheduled to close from 9 p.m. Sunday, Oct. 18, until 5 a.m. Monday, Oct. 19, between Exit 241 and Exit 243. Drivers will leave the highway at Idaho Springs, take County Road 314 east and rejoin I-70 at Hidden Valley. The eastbound Exit 243 off-ramp is expected to remain closed until 6 a.m. Friday, Oct. 23. The closure will allow crews to move eastbound traffic onto a newly completed bridge over Clear Creek. Westbound I-70 will close at Exit 244 from 9 p.m. to 5 a.m. on both Monday and Tuesday nights, Oct. 19 and 20. Drivers will use the U.S. 6 off- and on-ramps. The work involves grouting tendons in a segmental bridge being built roughly 20 to 30 feet above the existing westbound lanes. The Colorado Department of Transportation said the work depends on weather. If conditions require schedule changes, the eastbound closure could move to Oct. 25, the Exit 243 ramp closure to Oct. 25-30, and the westbound closures to Oct. 26 and 27. More overnight closures in both directions are expected from mid-November through mid-December. The $905 million Floyd Hill project spans eight miles between an area west of Evergreen and eastern Idaho Springs. Planned improvements include a third westbound lane that will operate as a tolled Express Lane, a missing stretch of frontage road, interchange upgrades, and wildlife and trail enhancements. Construction began in July 2023. The state expects westbound traffic to shift to a new alignment by the end of 2027, eastbound traffic by the end of 2028 and the project to be complete in 2029. Most funding comes from state sources, supplemented by a $100 million federal grant. The project is intended to address a two-lane bottleneck and improve travel-time reliability. A 2026 study estimated that congestion along the I-70 mountain corridor between Denver and Grand Junction costs the state about $2.25 billion annually: $1.9 billion in lost economic productivity, $319 million in residents’ lost time and $47 million in tourism revenue at risk. The study also estimated that visitor spending worth $2.3 million per hour is at risk when the corridor closes. Motorists can receive project text alerts by texting “floydhill” to 21000. The project information line is 720-994-2368.