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GENERAL REQUIREMENTS <br />MINIMUM DESIGN STANDARDS FOR STREETS <br />AND HIGHWAYS IN CITIES AND TOWNS <br />NEW CONSTRUCTION <br />The following general requirements shall apply: <br />(1) Design Loadings for Roadways: The design live <br />loading for streets and highways chat] not be less <br />than the current State of Washington maximum lapel <br />load. <br />(2) Vertical Clearance above the paved roadway <br />surface shall be a minimum of 16.5 feet. Vertical <br />clearance of structures above the walkway surface <br />shell be a minimum of 8.0 feet. <br />(3) Lateral Clearance: The lateral clearance <br />between curb face and the closest part of any fixed <br />object (excluding traffic control signs and break away <br />supports), shall be at least 3 feet. <br />(4) Bridges: Bridges shall be designed to the <br />requirements set forth in the latest AASHTO Standard <br />Specifications for Highway Bridges. Bridges shall <br />have a minimum roadway width of 28 feet. Sidewalks <br />shall be in addition. Design live loading for all bridges <br />shalt be not less than HS 20.44. <br />(5) Bridge Railings: Where an approach rail Is <br />required it will be made structurally continuous with <br />the bridge railing. Guardrail is required where speed <br />limits are greeter than 35 MPH. Other locations shall <br />be examined for the need for protection. If the <br />engineerinp study results in the decision that <br />protection Is not justified, documentation to that effect <br />should be retained. Railing height for pedestrian only <br />traffic Is 3'-80, for bicycles only is 4'-8', for comhined <br />Is 4'-8". When concrete barriers are used to separate <br />vehicles from pedestrian and bicycles, the 32' <br />concrete barrier shell have a metal rail extension <br />providing a total height of 4'-8". <br />(8) Roadway Geometrics: Design(s) shall be based <br />upon accepted engineering prat:tices and the require- <br />ments listed herein. <br />(7) Construction Specifications: Current editions of <br />Standard Specifications of the Washington State <br />Department of Transportation or the American Public <br />Works Assoclatiou shall be used. <br />(8) Traffic Control: All traffic control devices shall <br />conform to the Manual for Uniform Traffic Control <br />Devices (MUTCD) as modified by the Washington <br />Stale Transportation Commission, per RCW <br />47.36.030. <br />(9) Pedestrian Facilities: There shall be a minimum <br />5-foot clear surfaced walkway on each side of the <br />street unless topography or other special conditions <br />favor one walkway only. <br />(10) Ramps for the Handicapped: Ramps shall be <br />Included in all construction per RCW 35.68.075. <br />(11) Lane Width Criteria for One-way Streets: <br />Description Width <br />(a) Through traffic lane 10' (minimum) <br />I V (desirable)* <br />(b) Curb offset from through lane: <br />(1) On side with drainage. 2' <br />(2) On side without drainoge. 1' <br />(3) Traffic curb. 1' <br />(c) Special turn lane 12' <br />(d) Parking lane. 8' (minimum) <br />10' (desirable)" <br />The number of through lanes on a one-way street <br />shall be determined by the local agency on the basis <br />of local needs. <br />*IV minimum for exclusive bus lane. <br />0010' minimum for bus route with loading In parking <br />lane and in h!gh density areas. <br />P� <br />