Owl Creek-Brush Creek intersection won’t keep a passing grade without changes
Memo from engineer-consultants at SGM projects “Level of Service F” as growth continues
Snowmass Village Town Council members have spent years mulling over the possibility of a roundabout at the intersection of Owl Creek Road and Brush Creek Road.
The proposal includes pedestrian safety and traffic calming measures while addressing at times lengthy backups on Owl Creek Road, earning kudos from public safety officials, and also allows for some utility and infrastructure repairs and maintenance. Concerns about necessity, community interest in the project and town character have been the stickiest points of resistance.
But as the town continues to grow and traffic along with it, something will need to happen where Owl Creek Road and Brush Creek Road meet if that intersection is to keep its passing “Level of Service” grade based on stops and delays, according to a memo from the engineering and consulting firm SGM.
A team from SGM, along with a few Snowmass officials, presented traffic insights and a design overview at a Jan. 10 council work session; the design is about 30% complete, and the town has $500,000 allocated to more design work in 2022.
Overall, the intersection currently operates at a “Level of Service C” at peak times on a scale of A to F, where A represents “excellent operations” and “very little delay” and F represents “extreme congestion” and “excessive delay,” the memo states. For cars turning left from Owl Creek Road onto Brush Creek Road, the level of service is already at an F at peak times, according to the memo.
On the busiest days of the year — SGM looked at data from President’s Day weekend in 2019 and 2020 for their latest snapshot — that delay can result in a queue of more than 10 cars on Owl Creek Road in the peak afternoon hours, enough to block part of the fire station, SGM traffic engineer Dan Cokley told town council this week.
Take into account a 1% annual growth rate and the overall intersection grade drops to a “Level of Service D” with a queue of 18 cars backed up 100 to 150 feet past the fire station by 2027. If nothing were to happen at the intersection for the next two decades and growth continued at 1%, the intersection would be deep in “Level of Service F” territory in 2043 with a queue 80 cars long.
The growth projection is similar to what the Colorado Department of Transportation identified based on traffic counts near the Brush Creek Park and Ride on Highway 82, Cokley said.
That projected Level of Service D rating in 2027 is enough to trigger intersection improvements because of thresholds identified in earlier development studies for Base Village and Snowmass Center as well as the town comprehensive plan; both of those reports suggest any intersection at Level of Service C or above is “not a candidate for improvement,” according to the SGM memo.
The roundabout would take several years to design, phase and build. Starting the planning process now gives enough of a head start that the intersection would not drop below that Level of Service C threshold before improvements can happen.
A roundabout as currently proposed with 1% growth projections would likely keep the intersection at Level of Service B through 2043, and a bypass lane would not be necessary until 2066, Cokley said. At 2% growth, the bypass lane would come into play in 2043.
Other intersection improvements like a three-way stop, traffic signal control and mini roundabout have been considered, but none showed the same efficacy and intuitive use as a regular-sized roundabout, according Cokley and the town’s public works director, Anne Martens. A suggestion from Councilman Bob Sirkus to consider eliminating the left-turn option on Owl Creek Road didn’t gain any traction at the Jan. 10 meeting.
Across the Roaring Fork School District, three schools achieved higher ratings from 2019 to 2022, two schools had lower ratings during that time period and most remained the same.