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HomeMy WebLinkAboutKCM_RapidRide_I-Line_WSDOT_Clear Zone_City of Renton 1 December 13, 2024 Duffy McColloch Local Agency/Developer Services Engineer WSDOT – NW Region Development Services 15700 Dayton Avenue North Shoreline, WA 98133-5910 Project name: RapidRide I Line Project no: SR 515, MP 4.12 to MP 4.90  SR 515, MP 6.37 to MP 6.93 SR 405, MP 0.00 to MP 0.12 Subject: Design Clear Zone Dear Mr. McColloch, King County Metro is planning to modify existing routes within the cities of Renton, Kent, and Auburn, as well as portions of unincorporated King County to create the RapidRide I Line (I Line) bus rapid transit service. Throughout the project corridor, proposed I Line work elements include upgrading existing transit stops with new amenities, localized roadway improvements to support speed and reliability improvements for I Line operations and access to transit. Work by the RapidRide I Line project within the corridor will include portions of WSDOT state routes within the City of Renton: SR 515 (MP 4.12 TO MP 4.90, MP 6.37 to MP 6.93) • 108th Avenue SE  (SE 192nd St to SE 180th St) - 40 mph posted speed • Benson Drive S  (S 21st St to Talbot Rd S) - 40 mph posted speed • Talbot Road S  (Benson Dr S to 405 Limited Access) - 35 mph posted speed • SR 405 LIMITED ACCESS (MP 0.00 TO MP 0.12) • Talbot Road S  (SR 515 to S Grady Way)  - 35 mph posted speed Design Clear Zone The design clear zone distance required for streets with a posted speed of 35 mph or less is 10-feet and with a posted speed limit of 40 mph ranges from 10-19 feet, per Exhibit 1600-3, Design Clear Zone Distance Table, WSDOT Design Manual (M22- 01.22), October 2023. Section 1600.02(2), Design Clear Zone Inside Incorporated 2 Cities and Towns, states, “For managed access state highways within an urban area, it might not be practical or appropriate to provide the Design Clear Zone distances shown in Exhibit 1600-3. Roadways within an urban area generally have curbs and sidewalks and might have objects such as trees, poles, benches, trash cans, landscaping, and transit shelters along the roadside.” The section also states “For projects on city streets as state highways that include work in those areas that are the city’s responsibility and jurisdiction (see Exhibit 1600-2), design the project using the city’s development/design standards. The standards adopted by the city must meet the requirements set by the City Design Standards Committee for all arterial projects, bike projects, and federal-aid projects.” The American Association of State Highway and Transportation Officials (AASHTO), A Policy on Geometric Design of Highways and Streets, 2011, Section 7.3.4, Roadside Design (Rural and Urban Arterials), Lateral Offset, states “In urban environments for arterials, a lateral offset to vertical obstructions (e.g., signs, utility poles, luminaire supports, and fire hydrants, and including breakaway devices) is needed to accommodate motorists operating on the highway.” The section also states “Where a curb is used, the lateral offset is measured from the face of the curb. A minimum of 0.5 m [1.5 ft] should be provided from the face of the curb, with 1.0 m [3 ft] at intersections to accommodate turning trucks and improve sight distance.” In accordance with AASHTO, the proposed elements for the RapidRide I Line project will provide a minimum clear zone as described above. Sincerely, Chris Barnes City of Renton – Transportation Operations Manger 425-430-7220 cbarnes@rentonwa.gov Copies to: Janine Robinson, King County Metro Transit Kale Chang Yuen, King County Metro Transit John McKenzie, Jacobs Stephanie Forman, Forman Consulting