Traffic expert says expansion to 16 residents would add one evening trip; parking meets county code

Michael Lenhart, a traffic engineer accepted as an expert in the hearing, summarized the applicant's trip-generation memorandum (exhibit 21). Using Institute of Transportation Engineers (ITE) regression equations, he testified the existing 8-resident use generates about two morning peak-hour trips and four evening peak-hour trips; the proposed 16-resident occupancy would generate about two morning and five evening peak-hour trips—an increase of one evening trip. "The proposed expansion to 16 residents would generate... still 2 trips in the morning peak hour and 5 trips in the evening peak hour... it's considered a de minimis impact," Lenhart said.

Lenhart explained that the county's 2022 Transportation Review Guidelines define a de minimis impact as five or fewer peak-hour trips and that Transportation Service Area 1 allows high congestion thresholds. Civil designer Anthony Olexon testified the parking area was restriped to provide five stalls including one ADA space; county code parking for this use is one space per four residents (four spaces for 16 residents), so the site exceeds the requirement by one stall. Both experts and counsel told the examiner that, if the case advances to preliminary plan review, a transportation checklist may be used to confirm the de minimis finding and that no mandatory traffic impact study would be required under current guidelines.