Chapter 16.28
DIMENSION AND LAYOUT STANDARDS

Sections:

16.28.010    Rights-of-way.

16.28.020    Cul-de-sacs (dead-end streets).

16.28.030    Grades.

16.28.040    Intersections.

16.28.050    Alignments.

16.28.060    Street names.

16.28.070    Blocks.

16.28.080    Lots.

16.28.010 Rights-of-way.

A. Width Requirements.

Right-of-way

Designation

Minimum Widths (feet)

1. Minor Arterials

100*

2. All Other Roadways

60*

3. Alley

20

4. Walkway

10

* Except in cases where the approved right-of-way section of the comprehensive plan specifies a greater or lesser width as the minimum.

B. The areas of the right-of-way outside the street or curbs shall be graded to the street profile. Walkways shall be provided as may be required by the city. (Ord. 693 § 1, 1994)

16.28.020 Cul-de-sacs (dead-end streets).

The maximum length shall be 400 feet, and the terminal of such streets shall be a circular area with a minimum diameter of 80 feet, the improved portion (street) of which shall be 64 feet in diameter. (Ord. 693 § 1, 1994)

16.28.030 Grades.

The minimum grade on any street or road shall be 0.25 percent for purposes of drainage, and maximum grades shall not exceed 10 percent, unless otherwise approved by the planning commission. (Ord. 693 § 1, 1994)

16.28.040 Intersections.

A. Due regard should be given in every case to the topography of the area, the use of the right-of-way for utility purposes and its future use for rapid transit purposes.

B. Streets shall be required to intersect one another at an angle as near to a right angle as is practicable in each specific case.

C. The subdivider shall improve the extension of all subdivision streets to the intersecting paving line of any street. (Ord. 693 § 1, 1994)

16.28.050 Alignments.

The minimum requirements for all vertical alignment profile grade changes shall be connected with a vertical curve which shall have a minimum sight distance of 1,000 feet on primary streets, 500 feet for secondary streets and 300 feet on all others. (Ord. 693 § 1, 1994)

16.28.060 Street names.

Street names shall be approved by the planning commission and shall conform to the King County street system wherever possible. (Ord. 693 § 1, 1994)

16.28.070 Blocks.

A. The maximum length of blocks generally shall be 1,320 feet. Those over 900 feet shall have a crosswalkway at approximately the center of the block.

B. The width of blocks generally shall be sufficient to allow two tiers of lots.

C. Irregularly shaped blocks indented by cul-de-sacs and containing interior spaces will be acceptable when properly designed and fitted to the overall plat and when adequate provision is made for the maintenance of public areas.

D. Blocks intended for nonresidential use shall be designed specifically for such purposes with adequate space set aside for limited access off-street parking and delivery facilities.

E. Where frontage is on a main or secondary street, the long dimension of the block should be oriented with the direction of traffic flow. See CHMC 16.24.030 for high volume streets. (Ord. 693 § 1, 1994)

16.28.080 Lots.

A. All boundary lines of all lots shall be, as far as possible, at right angles to each other. Boundary lines that are proposed which are not a right angles will be carefully reviewed to determine whether the proposed boundary lines were designed to add required square footage to the proposed lot. Adjustments to boundary lines not at right angles which are proposed and which serve the primary purpose of meeting minimum required square footage requirements are not allowed. If it is determined that a proposed lot has insufficient square footage for a lot, absent the proposed area not at right angles with other proposed boundary lines, the proposed boundaries, proposed lots and proposed subdivision will not be allowed. The side lines of all lots, as far as practicable, shall be at right angles to the street which the lot faces, or radial or approximately radial if the street is curved.

B. No lots shall be divided by the city boundary line.

C. Lot numbers shall begin with the number 1 and shall continue consecutively throughout the block.

D. Lots must contain frontage on a public right-of-way.

E. Lots other than corner lots may front on more than one right-of-way where, in the opinion or the planning commission such is necessitated by topographic or unusual conditions. Where lots front on more than one right-of-way, adequate guarantees shall be made to assure that all structures constructed on a series of such lots face the same right-of-way. (Ord. 705 § 5, 1994; Ord. 693 § 1, 1994)