Commission debates driveway vs. private roadway rules; asks fire authority for technical guidance

Emigration Canyon planning commissioners spent substantial time on Jan. 9 reviewing proposed changes to site-access definitions and related standards, aiming to clarify when a private access should be treated as a driveway, a shared driveway, or a private roadway and what engineering or fire-access standards should apply.

Commission staff presented proposed language that would treat a driveway as access serving a single detached single-family dwelling and would treat a private roadway as primary access for multiple dwellings. The draft included a practical-distance approach (150 feet) to distinguish when a driveway should be improved to get emergency services close to a structure; commissioners and staff debated whether length alone is the right test or whether the number of units served should be decisive.

Key technical points discussed: - Fire apparatus turnaround: participants discussed a 50-foot practical distance and the related requirement to provide a turnaround (a "hammerhead" or equivalent) once a fire access lane exceeds a certain length. - Distance threshold: staff proposed that a driveway longer than 150 feet be treated as a private roadway for improvement purposes; some commissioners urged caution about using length alone as the trigger. - Width and structural standards: the commission reviewed existing language that calls for private roadways to provide 20'24 feet of unobstructed travel surface (varying references appeared in the draft), with a wider cross-section (24 feet) required for certain longer cul-de-sacs (e.g., where legs exceed 500 feet). The transcript also cited an 80,000-pound design standard for fire access lanes in current codes, and older references to a 24-ton vehicle standard that participants flagged as likely outdated. - Units-served threshold: the draft suggested distinguishing shared driveways (serving two single-family detached homes) from private roadways (initially suggested as serving three or more), but commissioners discussed whether the threshold should be two or three homes and whether separate definitions for "shared driveway" are necessary.

Commissioners asked staff to get technical input from the fire authority (Unified Fire) and the county building/fire code officials before adopting final language. They also noted county code chapter references (chapter 14 roadway categories 1-6, which currently allow narrower widths for dirt/gravel canyon roads) and suggested providing typical cross sections for driveways, private roadways and public streets in the standards.

The commission did not finalize numeric thresholds at the meeting; it directed staff to: (1) invite the fire authority to the next meeting for technical clarification; (2) confirm which Wildland-Urban-Interface (WUI) standard is in effect locally (transcript referenced a 2006 Utah WUI guide and noted a 2021 update exists); and (3) draft clearer definitions and cross sections for review.

Commissioners emphasized that the definitions section should distinguish terms and point to the detailed engineering standards elsewhere in code rather than try to capture all technical requirements in a single definitional paragraph.