CHAPTER 2
STREET CONSTRUCTION
SECTION:
8-2-1: Conformance To Plan Required
8-2-4: Additional Right Of Way Dedication
8-2-5: Construction Standards And Specifications
8-2-10: Street Improvements Responsibility
8-2-1 CONFORMANCE TO PLAN REQUIRED:
The location of all streets and roads shall conform to the official major thoroughfare plan, which may include a major street plan. (Ord. 836, 7-13-2009)
8-2-2 EXTENSIONS:
The proposed street system shall extend existing streets or projects in accordance with required width. (Ord. 836, 7-13-2009)
8-2-3 REQUIRED WIDTHS:
The minimum width of right of way, measured from lot line to lot line, shall be provided in accordance with the design standards and guidelines for streetscape elements adopted pursuant to title 11 of this code. In cases where topography or other physical conditions make a street of the required minimum width impracticable, the public works director or city engineer may modify the requirements of this section. (Ord. 836, 7-13-2009)
8-2-4 ADDITIONAL RIGHT OF WAY DEDICATION:
A. Adjoining Existing Streets: Subdivisions, plats or short subdivisions that adjoin existing streets shall dedicate additional right of way to meet the minimum street width requirements of section 8-2-3 of this chapter.
B. Location On Both Sides Of Existing Street: The entire right of way shall be provided when any part of the subdivision, plat or short subdivision is on both sides of the existing street.
C. Location On One Side Of Existing Street: When the subdivision, plat or short subdivision is located on only one side of an existing street, one-half (1/2) of the required right of way, measured from the centerline of the existing roadway, shall be provided. (Ord. 836, 7-13-2009)
8-2-5 CONSTRUCTION STANDARDS AND SPECIFICATIONS:
A. Grading: Roads shall be designed in accordance with AASHTO’s "A Policy On Geometric Design Of Highways And Streets" dated 2004. All streets shall be graded from property line to property line. Fill slopes shall be flatter than four to one (4:1). Finished street grade will conform to the approved plan. Street vertical alignment shall not be less than 1.0 percent to permit free flow of stormwater, or greater than twelve percent (12%). Maximum and minimum street grades and slopes may be exceeded where the terrain will not permit installation of streets within specified limits, or for other good reasons as determined by the city engineer.
B. Preparation Of Roadbed: The surface of roadway shall be true to line, grade and section indicated on the approved plans and thoroughly compacted (95 percent maximum density section 2-03.3(14)D of the APWA standards) before base material is placed. Roadbed or subgrade preparation shall conform to division 2-06 of the APWA standard specifications. Base material shall not be placed until:
1. The city has inspected and approved the material and the grade upon which it is to be placed. The city may require certification that the furnished materials comply with appropriate state specifications;
2. The sidewalk areas, the curb excavation, side streets and driveway approaches, where indicated, have been shaped, dressed, and ballast subgrade entirely completed;
3. All under the street utilities located in minor trenches less than four feet (4') in depth shall be installed and compacted with backfilled, crushed, surface grade materials (per section 9-03.9(3) of the APWA standards). Major trenching for utilities may be engineered and made with engineered backfill according to section 7-10.3(11) and section 2-09.3(1) of the APWA standards. Base course shall be crushed gravel with a minimum compacted depth of nine inches (9") (95 percent maximum density per section 2-093.3(14)(D) of the APWA standards) and will extend under the curb lines. Engineering analysis may be accepted to reduce this depth, where appropriate.
C. Street Surface: The applicant shall submit a pavement design for the city’s review and approval, stamped by a Washington state licensed engineer. At a minimum, pavement section shall consist of a roadway top course of crushed surfacing top course (per section 9-03.9(3) of the APWA standards) with a minimum compacted depth of four inches (4") (95 percent WSDOT no. 66) per APWA standards. Wearing surface of roadway shall be asphaltic concrete pavement, with a minimum compacted depth of two inches (2"). Aggregate materials shall conform to sections 9-03.9(1), 9-03.8(2) and 9-03.8(3) of the APWA standards. Asphaltic materials and construction methods shall conform to division 5-04 of the APWA standards. Roadway will be inspected by the city after installation of crushed rock, and again after surfacing with asphaltic concrete.
D. Horizontal Curves: Where a deflection angle of more than ten degrees (10°) in the alignment of a street occurs, a curve of reasonably long radius shall be introduced. On streets sixty feet (60') or more in width, the centerline radius of curvature shall be not less than three hundred feet (300'); on other streets, not less than one hundred feet (100'), unless specified otherwise by the public works department or the city engineer.
E. Vertical Curves:
1. All changes in grade shall be connected by vertical curves of a minimum length of two hundred feet (200') unless specified otherwise by the public works department or the city engineer.
2. Profiles of all streets showing natural and finished grades shall be drawn to a scale of not less than one inch equals one hundred feet (1" = 100') horizontal and one inch equals twenty feet (1" = 20') vertical, when required by the public works department or the engineer.
F. Reverse Curve Tangents: A tangent of at least one hundred feet (100') in length shall be introduced between reverse curves on arterial and collector streets.
G. Minimum Centerline Offsets: Street jogs with centerline offsets of less than one hundred twenty five feet (125') shall not be allowed. (Ord. 836, 7-13-2009)
8-2-6 DEAD END TURNAROUNDS:
A. Dead end streets are minor terminal streets or courts designed to have one end permanently closed. Those streets shall be provided at the closed end with a paved turnaround having an outside roadway diameter of at least eighty feet (80') and a street right of way diameter of at least one hundred feet (100'), unless an alternative design is specified per the design standards and guidelines for small lot and multi-family development or the design standards and guidelines for streetscape elements adopted pursuant to title 11 of this code.
B. Where, in the opinion of the public works director, it is desirable to provide for street access to adjoining property, proposed streets shall be extended by dedication to the boundary of such property. Such dead end streets shall be provided with a temporary turnaround having a right of way diameter of at least eighty feet (80'). (Ord. 836, 7-13-2009)
8-2-7 PRIVATE STREETS:
All private streets shall adhere to the requirements within this chapter. The city shall receive full easement rights over, under, across and through said street for fire, aid, police, utility and any other municipally related aspect. The city shall regularly inspect the streets to make certain they are kept properly maintained. The city shall not assume any responsibility for private street maintenance. If a homeowners’ association is formed and will be responsible for the maintenance of the private street, a copy of the covenant will be filed with the city. (Ord. 836, 7-13-2009)
8-2-8 STREET NAMES:
A. Manner Of Naming: Proposed streets which are obviously in alignment with others already existing and named shall bear the names of the existing streets. Others shall be named in accordance with the city street naming and numbering system.
B. Authority To Change; Notice: The city council shall have the authority to change street names or numbers to maintain consistency and harmony in the city. In making any such change, the council shall consider the impact such change may have on existing businesses and residences, and on the responsiveness of emergency services. The city shall mail notice of any intent to change a street name at least sixty (60) days prior to the intended effective date of the change, and a notice shall similarly be published in the local newspaper. (Ord. 836, 7-13-2009)
8-2-9 BLOCKS:
Blocks shall not exceed six hundred feet (600') in length, or a shorter length when specified for a street type identified in the city’s design standards and guidelines for streetscape elements. The maximum length may be increased if the public works director or city engineer determines it necessary to secure efficient use of land or desired features of street pattern. (Ord. 836, 7-13-2009)
8-2-10 STREET IMPROVEMENTS RESPONSIBILITY:
Street improvements shall be the sole responsibility of the party that is either dedicating the street or requesting the need for the access of the undeveloped portion of a dedicated street. (Ord. 836, 7-13-2009)