Thirstston County rolls out proposed 2026 road-standards update, seeks public comments

Thirstston County Public Works on Tuesday presented a proposed 2026 update to the county’s road standards, saying the rewrite improves readability and adds technical requirements intended to ease design review and strengthen safety reviews for new development.

Development Review Manager Todd Mason opened the briefing and identified County Engineer Matt Osman, design staff member Brian Meyer and traffic staff Becky as presenters. Mason said the current standards date to 2018 and the draft consolidates duplicate rules, clarifies as-built deliverables and adds new guidance on plan formats and roadside design.

The draft sets a standardized block on plan sheets for county (and partner city) acceptance stamps to prevent stamps from covering plan information and asks designers to provide as-built layers that support the county’s asset-management systems. “We’ve updated the requirements on that,” Mason said, adding that clearer deliverables will help design teams anticipate needs during bidding and simplify transfer to asset-management.

Traffic and safety requirements are a notable change. Becky said Thirstston County will require traffic-impact analyses (TIAs) to include a predictive safety analysis that follows Washington State guidance and the AASHTO Highway Safety Manual process to estimate potential collisions and mitigation needs caused by added development traffic. “You should include a safety analysis,” Becky said, explaining the predictive method used to quantify crash risk.

Street design updates emphasize maintenance and sight-line management. Mason said the draft favors concrete for roundabouts and refuge islands to lower maintenance needs and reduce vegetation that can impede sight lines. The county also proposes roadside planter strips for stormwater management and an allowance for one-way streets where topography makes two-way design infeasible.

On roadside clear zones, Brian Meyer told designers to reference national roadside guidance when sizing buffer distances. “Most of our roads that are, you know, 35 and less, it is 10 feet, but it does vary,” Meyer said, adding that clear-zone width depends on speed limit, slope and roadside geometry.

The draft also addresses operational issues tied to private roads: Mason said recurring problems occur when garbage and recycle bins are placed on narrow private drives and that the standards will ask developers to reserve space for collection areas in developments of roughly four lots or more.

Bridge and construction chapters were updated to reference applicable bridge-geometrics standards and to tighten construction-control and inspection requirements. Mason said the county is aligning submittal requirements and material testing with capital-project practice because developer-built roads often become county-maintained infrastructure.

Staff outlined the schedule for public input and adoption. Mason asked for comments by the end of June (the presentation originally stated “June 31,” which was a calendrical error; staff clarified the intended deadline is June 30). County Engineer Matt Osman said staff will review public and industry feedback, request a public hearing before the Board of County Commissioners and hopes to complete adoption by the end of summer.

Mason provided contact information for follow-up questions (ToddMason@co.thirstston.wa.us; desk phone 360-867-2042) and Zach closed the session by encouraging stakeholders to submit comments.

Next steps: staff will collect and review comments, schedule a public hearing before the Board of County Commissioners and return to the board with a draft for adoption consideration.