Flex Berthoud Holiday Parade Detour. Effective December 6 2025 from 5 p m to 8 p m . Southbound: Right on Welch Ave, Right on Berthoud Parkway, Left on Mountain Ave, Resume normal routing. Northbound: Right on Berthoud Parkway, Left on Welch Ave, Left on 1st Street. Resume normal routing. Stops closed at Mountain and 3rd, Mountain and 2nd. Temporary stops Northbound and Southbound at Welch and 3rd Ave.