Ada County proposes two-service-area impact-fee map; Garden City raises equity, local-benefit concerns

Justin Lucas with the Ada County Highway District (ACHD) told the Garden City City Council on Sept. 22 that ACHD is proposing to split its existing single service area into two service areas for transportation impact fees and that the change would produce different fee levels across Ada County.

Lucas said the proposal stems from a multi-year update to ACHD’s capital improvements plan and from analysis of travel patterns and project needs. “This is part of a public outreach process that we're undergoing, through the month of September and and the next several weeks, just seeking as much input as we can about this project,” Lucas said.

The draft plan released to councils would treat parts of Ada County as distinct service areas so fees better reflect where capacity-expansion projects are needed. Lucas said the agency projects 20 years of growth, aggregates capacity-expansion projects needed on arterial roadways and then allocates a share of those project costs to new development through formula-driven fees. He said the countywide average trip length used in ACHD’s modeling is about 7.4 to 8 miles, and that ACHD uses regional travel-survey data (Compass) and aggregated trip-data products (Replica) to estimate travel patterns.

Why it matters: The service-area split changes how much a developer would pay depending on location. Lucas showed sample rates from the draft fee table: a single-family home in the proposed West Service Area would face roughly a $8,900 impact fee while the same home in the East Service Area would face about $5,300, reflecting different bundles of projects identified in each area.

Council members pressed ACHD staff on local impacts and eligibility of non-road projects. Councilmember Page and others said Garden City has limited greenfield development and questioned whether the proposed impact-fee revenues would yield any projects inside Garden City. Lucas said the draft identifies few impact-fee-eligible arterial projects inside Garden City and that many of the area's trips rely on countywide roadways outside the city. He added that ACHD separately pursues federal and local funding sources for sidewalks, bikeways and other local facilities but that impact fees under current state law are generally limited to capacity-expansion needs attributable to new development.

On bicycle and pedestrian funding specifically, Lucas said standalone bicycle projects and efforts to remedy existing deficiencies are typically not eligible for impact-fee funding under state law. "No. ACHD's impact fee program does not include in any scenario bicycle and pedestrian facilities," he said, adding that some bicycle/pedestrian elements included in new roadway construction may be eligible when they are part of a capacity-expansion project.

Council members also asked about project design choices such as roundabouts versus traffic signals. Lucas said ACHD’s traffic analyses generally start from a preference for roundabouts when the modeling shows they will function safely and efficiently; signals are built when a roundabout would not meet performance or safety needs.

Next steps: Lucas said ACHD planned a formal public release of the draft and will gather input from jurisdictions and the public through October to inform the highway district commission’s final decision. He encouraged councils that want presentations to request them.

Garden City context: Council members repeatedly said the city feels disadvantaged because it has little greenfield development to generate impact-fee revenue and thus sees fewer impact-fee-funded projects inside its boundaries. ACHD staff acknowledged that point and said the two-service-area approach was partly adopted to respond to such feedback.

No formal action on the ACHD plan was taken by the Garden City Council at the meeting; ACHD sought input and said it will accept public comments during its outreach period.