Shoreline Planning Commission Meeting – February 17, 2022: Transportation Master Plan Update

The Shoreline Planning Commission met on February 17, 2022, to receive a study item presentation on the Transportation Master Plan (TMP) update, focusing on auto level of service (LOS) options. Senior Transportation Planner Nora Daly Peng and City Traffic Engineer Kendra Nadinsky presented the third in a series of briefings, covering four LOS options for intersections and supplemental volume-to-capacity (V/C) ratio standards. The meeting began at approximately 6:15 PM (local time) and adjourned after discussion with no public comment or other business.

Discussion Items

• Presentation Overview: Staff explained that the TMP is a long-range multimodal blueprint last updated in 2011. The update aims for adoption by end of 2022. The project team has conducted two outreach rounds and is developing modal plans for walking, biking, transit, shared-use mobility, and auto/freight.

• Auto Level of Service Options: Four options were presented:

  • Option 1 (Status Quo): Maintain LOS D at signalized intersections citywide (LOS B on state routes). Pros: simplicity, lowest vehicle delay. Cons: high cost for widening, harms walkability/bikability, highest transportation impact fees.
  • Option 2A: Allow LOS E at intersections adjacent to higher-density zoning; retain LOS D elsewhere. More context-sensitive but has edge issues and pockets with weak transportation options.
  • Option 2B (Staff Preferred): Allow LOS E in candidate countywide centers (148th St, 185th St, Shoreline Place), LOS D elsewhere. Better focused, fewer edge issues, aligns with growth centers.
  • Option 3: Use a corridor-averaging method allowing LOS E average along key corridors in denser areas. Most flexible but complex, allows highest delay, and may be perceived as arbitrary.

• Modeling Results: Using 2019 baseline and 2044 projections, the number of failing intersections (by current D standard) would be 6 under Option 1, 5 under Options 2A/2B, and 3 under Option 3. Future V/C ratio analysis showed 9 corridor segments failing the current 0.9 standard, reducing to fewer than half under a 1.1 standard in centers.

• Supplemental V/C Ratio Options: Three options: (1) Keep 0.9 on all principal/minor arterials; (2) Remove standard; (3) Sync with Option 2B – allow 1.1 in centers, 0.9 elsewhere. Staff preferred Option 3 for consistency and context sensitivity.

• Commission Discussion: Commissioners asked about cut-through traffic, pedestrian and bicycle impacts, freight delay, and modeling assumptions. Vice Chair Rebecca expressed support for walkability. Commissioner Malik inquired about shared-use mobility hubs and the 185th St bridge. Staff noted that the 185th area would see higher delay intentionally to discourage auto-dependence.

Key Outcomes

• No formal votes were taken; the study item was for discussion and feedback.
• Staff indicated that Option 2B (centers-based LOS E) emerged as the preferred balance, and they will return to the Planning Commission on March 17, 2022, to present project prioritization and performance measures.
• Draft modal plans will be debuted in early April, with third outreach series launching mid-April.
• Commission members expressed appreciation for the detailed presentation and look forward to future updates.

Note: The meeting had no consent calendar, public comments, or other business. The next scheduled meeting on March 3 was canceled; the next meeting is March 17, 2022.