Folsom council adopts roundabout design standards, directs staff to prioritize Riley Street corridor study

FOLSOM, Calif. — The Folsom City Council on Feb. 25 adopted new planning and design standards for roundabouts and instructed staff to prioritize further engineering work on a set of intersections on Riley Street, with additional corridor analysis to include a Riley–Wales concept.

The council’s action came after staff and consultant presentations of a roundabout feasibility study covering 13 intersections, discussion of a multi-criteria scoring system and cost estimates, and a public comment urging attention to business access concerns on East Bidwell and corridor continuity.

City staff said the feasibility study, funded partly by a $400,000 SACOG grant and local match from STA, screened 13 intersections and identified nine that merit further engineering. The presentation named three adjacent Riley Street intersections as top priorities because they offer corridor-level circulation and place-making opportunities while fitting largely within existing right of way. Consultant Steven Dillon of Kimley Horn described the method: “the process ... all started with, the city's 2035 general plan” and emphasized safety and multimodal considerations in scoring.

The study found two intersections (referred to in the report as Intersection 3 and Intersection 11) infeasible for roundabout control because of bridge proximity and extensive lane requirements that would require substantial right-of-way acquisition. Of the remaining locations, the Riley Street group (three closely spaced roundabout concepts) scored highly for safety, multimodal benefits and lower probable construction cost. Staff recommended moving those three forward first and performing deeper engineering and performance-measure analysis to prepare competitive grant applications.

Council members asked for performance metrics that go beyond traffic operations and safety to quantify effects on business access, pedestrian and bicycle accommodations, and local air-quality benefits. Councilmember Werbaugh said she wanted to ensure the study addresses “accessibility to our current businesses,” particularly along East Bidwell, and suggested staff analyze whether intervening turn pockets or alternative access can preserve business access where roundabouts would otherwise limit direct left turns.

Public commenter Dan Dreher, who served on the advisory committee, urged the council to note differences between corridors: “we came up as a committee as a first step plan to to look at Riley Street First only because of the inner interaccessibility … the roundabouts did not create any disadvantages to the businesses,” he said, while cautioning that East Bidwell has different constraints.

Council discussion produced direction that staff should: implement the newly adopted design standards; advance detailed engineering for the three Riley Street roundabout concepts (Riley at Bidwell, Riley at the Coles driveway and Riley at Lehi); attempt to add a Riley–Wales concept within the available study budget; and keep the remaining higher-scoring intersections on an implementation list to pursue with grant funding as resources allow. Several council members said they prefer focusing limited city engineering funds on projects that deliver measurable safety and traffic-flow benefits.

The council voted unanimously to adopt resolution 11,331, formally establishing the roundabout planning and design standards, and to give staff the prioritization direction described above. Staff said the designs shown were conceptual and that any project moving to final design would include community engagement and more detailed driveway-access, signage and multimodal accommodations.

Next steps for the prioritized Riley corridor work include drafting performance measures (air quality, pedestrian and bicycle counts, driveway-access impacts and safety metrics), detailed cost refinement, and targeted grant-readiness work timed for upcoming regional and state funding rounds.

The consultant and city staff are expected to return with refined engineering, estimated costs and specific performance measures before seeking construction funding or design approvals.