Ada County Highway District representative Justin Lucas told the Boise City Council that ACHD’s 2025 Capital Improvement Plan update — and an accompanying public review draft of a revised impact fee program — would raise impact fees countywide and proposes moving from a single service area to a two‑service‑area model for fee collection and project allocation.

Lucas said the draft shows a technical justification for two service areas based on travel patterns and modeling, and he described the effect on common land‑use categories: "For a single family home in the West Service Area, it's approximately $8,900. In the East Service Area, it's approximately $5,300," up from about $3,900 under the current single service‑area structure, he said. He added that a single service area projected under the same model would result in an impact fee of a little over $7,000 per single‑family home.

The change is driven largely by updated project lists and higher construction cost estimates, Lucas said. He described four technical topics the district reviewed — service areas, which project types to include in the CIP, the analysis time horizon, and the collector network — and said ACHD hired a consultant and performed peer reviews and public outreach before producing the draft. "Everything we do within our CIP and capital improvements plan and our impact fee program is governed by state law," Lucas said, adding that ACHD relies on Compass travel modeling using member jurisdictions’ comprehensive plan inputs to translate projected growth into roadway projects.

The draft two‑service‑area boundary concentrates a greater number of modeled roadway and intersection projects on the West side of Ada County, which is why proposed fees there are higher, Lucas said. He described trip‑shed statistics from the modeling as a technical justification: roughly three‑quarters of trips that originate in the West Service Area stay in that area, while the East Service Area’s internal trip share was in the low‑to‑mid‑60s percent range. Lucas said average trip length within Ada County is about eight miles, which limits the ability to draw very small service areas that meet the travel shed threshold.

Council members asked technical and policy questions. Councilwoman Corliss asked whether a project on a boundary such as Cole Road would be funded from one side or the other; Lucas replied, "A portion of the impact fees collected from one side can support that project and a portion from the other side can support that project." Councilman Halliburton pressed on how ACHD decides whether to include full project cost (design, right‑of‑way and construction) or a smaller scope such as only preserving right‑of‑way; Lucas said modeling shows when a project is likely to be needed and staff typically include full scope for projects triggered in the early years of the 20‑year CIP and may put only right‑of‑way preservation for projects forecast in the later years.

Lucas also described procedural safeguards for developers: the impact fee program includes an individual assessment process so a project proponent can dispute how fees apply to a specific development. He explained that state code requires projects included in the CIP to be justified by travel demand modeling, and that ACHD cannot add arbitrary projects to raise fees. Lucas noted administrative tools exist to loan funds between service areas if needed, but doing so increases bookkeeping complexity.

The draft is out for public review on ACHD’s website, Lucas said, and the commission will receive public feedback and community responses from cities and the development community before the commission deliberates toward adoption. "As part of our update to the commission in November, we will be providing them with essentially feedback that we've received on this idea from each community," he said.

The ACHD proposal would increase fees in every scenario presented; the central choices for policymakers are whether to keep a single service area (projected around $7,000 per single‑family home under the new cost assumptions) or adopt two service areas with the West paying more than the East.

Looking ahead, ACHD staff said they expect to refine the CIP project list as they receive feedback from the development community and partner jurisdictions; reducing project scope or removing projects from the CIP will reduce the resulting impact fees. Final adoption rests with the ACHD commission after the public outreach period.