Kirkland reviews preliminary transportation impact fee study; consultants propose square‑foot scaling for housing

Kirkland officials reviewed preliminary results of a city transportation impact fee study during the April study session, with consultants recommending a trip‑based fee schedule that scales residential charges by square footage to comply with 2023 changes to Washington law.

The study, presented by Kevin Pellstreng, the city's financial planning manager, and consultants from FCS Group and DKS, lays out a framework that divides the cost of planned capacity‑increasing transportation projects by forecast growth in trip ends. John Ghiliducci, a consultant with FCS Group, said the analysis relies on regional trip generation modeling and a project list provided by DKS.

The study finds 21,103 new trip ends over the forecast period and an estimated net allocable project cost of about $112 million after subtracting existing impact fee balances. That produces a calculated cost per trip end of roughly $5,310, "just a skosh lower" than the city's previous estimate, Ghiliducci said.

Why it matters: state law revised in 2023 requires jurisdictions to scale impact fees so smaller dwelling units pay lower fees. The consultants said they applied trip generation as the basis for transportation fees and then scaled the residential charge by square footage using local dwelling size data. That yields a per‑square‑foot charge the consultants described as $4.39 per square foot in their example; the framework produces a minimum and maximum fee for single‑family houses based on occupancy and a square‑foot cap to avoid charging larger houses beyond the point where more floor area does not mean more occupants.

Council members pressed consultants on two technical choices that materially affected the fee level. First, DKS supplied the trip forecast; the consultants used trip ends (an origin or a destination counts as one trip end) so trips that both begin and end inside Kirkland count twice. Second, DKS and the consultants assigned an "eligibility" percentage to each project on the capital list to reflect what share of a project increases capacity for future users and therefore can be funded with impact fees. That assignment lowered the share of the $321 million project list found eligible compared with the city's 2021 study, producing about $113 million in eligible costs instead of the earlier study's higher share.

Council members asked whether grouping projects into broad programs (for example, a citywide safety striping program) made it harder to show that the program projects add capacity. Doug Gabbard of FCS Group said eligibility was decided project by project; if the project descriptions were unclear and a project did not appear to add capacity, it received a low or zero eligibility percentage. Staff said they would follow up with DKS to confirm labels or nomenclature did not depress eligibility assignments.

Several council members asked for illustrative examples showing how scaling affects small dwellings, cottages and ADUs. The consultants and staff said smaller units would generally see reduced fees under the square‑foot scaling approach and offered to return with concrete examples for smaller sizes (for instance, a 1,400‑square‑foot home) to show expected decreases.

Points of technical clarification noted by staff and consultants - Trip forecast denominator: 21,103 trip ends added during the forecast period (DKS/BKR model). - Eligible project costs used as the fee numerator: about $113,000,000 after applying project‑level eligibility percentages and subtracting the existing impact fee fund balance. - Calculated cost per trip end: roughly $5,310. - Scaling approach: transportation fees are trip‑based; residential scaling is by square footage, producing a per‑square‑foot charge the consultants presented as an example ($4.39/ft2) with a minimum per‑person floor and a maximum to limit fees on very large single‑family homes.

Next steps: staff and consultants will return with more granular examples of how scaling affects smaller unit sizes and options for handling multifamily and ADU types. The city manager said the council will see draft fee ordinances for transportation, fire and parks at a future meeting after additional review.

Lede provenance: "first item is the discussion of our transportation impact fees." (transcript 990.165)

Ending: The study session provided a technical first look at a new trip‑based, square‑foot scaled approach to transportation impact fees; staff and consultants will bring back worked examples and follow up on project eligibility questions before the council considers ordinance adoption.