31-22 STREETS. — Danville Zoning Code

31-22.1 General Provisions. ¶

a. Conformance to General Plan . The design, layout, width, circulation, and other design aspects of streets in a subdivision shall conform to the locations which may have been shown on the General Plan or in all cases shall provide advantageous development for the general planning area within which the subdivision lies.

b. Reserve Strips . Reserve strips controlling the access to streets or other public rights-of-way shall not be approved unless such strips are necessary for the protection of the public welfare or property rights.

c. Designation on Final Map or Parcel Map . The final map or parcel map shall show the monument line of each street, the boundary of each street, including the width of the portion of any fractional street being dedicated, the width of existing road rights-of-way from public records, and the widths on each side of the monument line of whole streets. The widths and locations of adjacent streets shall be shown as determined from public records. Whenever the Engineering Department or the City Engineer has established either the centerline or monument line of the street and such reformation is made a public record, this location and data shall be shown on the final map or parcel map.

d. Angle of Intersection . All streets shall intersect as nearly as possible at right angles.

e. Centerlines . Streets entering on opposite sides of any given street shall have their centerlines directly opposite each other, or the centerlines shall be offset by at least one hundred fifty (150') feet.

f. Distance Between Streets . The minimum distance between streets entering a thoroughfare shall be eight hundred (800') feet.

g. Block Length . Block lengths shall not exceed one thousand (1,000') feet.

h. Street Name Approval . Street names shall be subject to the approval of the Planning Department.

i. Street Name Signs . The subdivider shall furnish and install necessary street name signs in accordance with details approved by the Engineering Department.

j. Conditions Requiring Grade Separation . If a subdivision borders on, or contains a railroad right-of-way, a limited access freeway, or similar type of facility, the advisory agency may require that the street plan be considered in its relation to the probability of grade separation.

k. Classification . The classes of streets shall be as follows: thoroughfares, arterials, collectors, minors, industrial streets and private roads.

l. Traffic Safety Devices . The subdivider shall furnish and place such traffic safety devices within, or adjacent to, the subdivision as may be specified by the Engineering Department.

m. Intersections .

Street intersections shall be designed to provide reasonable approaches from side streets, and to provide smooth continuous flow of drainage without overflow across the intersection.
Valley gutters shall be provided to carry drainage across intersections only if underground drainage facilities cannot reasonably be provided. Valley gutters shall not be permitted across arterial streets. Valley gutters shall by on a continuous minimum grade of one (1%) percent, reduction of which may be approved by the Engineering Department.

31-22.2 Width. ¶

a. Minimum Requirements . The minimum width of pavement and rights-of-way of the various classes of streets shall be as shown on the following table:

	*Width of*	*Pavement*	*Class*
*Class*	*w/curbs*	*w/o curbs*	*Right-of-way*
	*Width of*	*Pavement*	*Class*
*Class*	*w/curbs*	*w/o curbs*	*Right-of-way*
Thoroughfares and arterials
Two-lane	40 feet		60 feet
Four lane undivided	64 feet	64 feet	84 feet
Four-lane divided	80 feet		100 feet
Industrial two-lane	48 feet		68 feet
Industrial four-lane	64 feet		84 feet
Collector streets	36 feet	36 feet	56 feet
Minor streets	32 feet	36 feet	52 feet
Private roads		16 feet	25 feet

b. Measurement . The width of roadway shall be measured normal to the centerline between the top face of the curbs, or edges of the pavement, not including roadside ditches.

c. Exceptions . Exceptions to the widths set forth in paragraph a., because of terrain conditions in hillside areas, shall be considered on the basis of cross-sections and other evidence to be submitted by the subdivider.

31-22.3 Grades. ¶

a. Maximum Limits . Maximum street grades shall not exceed the following limits:

Arterial streets, eight (8%) percent;
Collector streets, fifteen (15%) percent;
Minor streets, twenty (20%) percent;
Private road, twenty (20%) percent;
Driveway, twenty-five (25%) percent.

b. Minimum Limits . The minimum uniform grade for all classes of streets shall not be less than one (1%) percent, except reduction to not less than one-half (1/2) of one (1%) percent may be authorized by the Engineering Department.

c. Pavement Across Intersection . The grade of the pavement surface across an intersection shall not be more than six (6%) percent.

d. Streets Entering Intersection . The centerline grade of each street entering an intersection shall not be more than six (6%) percent within a distance of thirty (30') feet from the nearest curbline of the intersected street.

e. Vertical Curves . Changes of grade in vertical alignment of streets shall be made with parabolic vertical curves. The

design of such curves shall be in accordance with standards outlined in the California Division of Highways “Highway Design Manual.”

“Stopping sight distance” shall be provided for the following design speeds:

(a) Arterial and industrial streets, forty (40) miles per hour;
(b) Collector streets, thirty (30) miles per hour:
(c) Minor streets, twenty (20) miles per hour;
(d) Private roads, fifteen (15) miles per hour.

“Headlight sight distance” shall be provided for sag vertical curves in accordance with these requirements, except where installation of street lights eliminates any sight restriction due to lighting.

f. Minimum Length of Vertical Curve . The minimum length of a vertical curve shall be fifty (50') feet for minor streets and private roads, one hundred (100') feet for collector streets, and two hundred (200') feet for arterials.

g. Earth Slopes in Cuts or Embankments . Earth slopes in cuts or embankment sections shall not be steeper than one and one-half (1 1/2') feet horizontal to one (1') foot vertical, unless steeper slopes have been approved based on a report submitted by a soil engineer. The soil report shall be filed with the Public Works Department.

h. Horizontal Curves .

Changes in direction of the streets shall be made with horizontal circular curves, with the edges of the pavement and curblines parallel to and equidistant from the centerline of the right-of-way.
The radius of curvature in the centerline of the street shall not be less than:

(a) Arterial street, six hundred fifty (650') feet;
(b) Collector street, two hundred (200') feet;
(c) Minor street, seventy-five (75') feet;
(d) Private road, twenty-five (25') feet.

31-22.4 Pavement. ¶

a. General . The structural design of the pavement includes the determination of the thickness and type of subbase, base, and surfacing to be placed over the basement soil according to an accepted method used by the Engineering Department. The Engineering Department shall specify the structural design for the streets.

b. Soil Tests . The subdivider, at his expense, may make tests of the soil over which the surfacing and base is to be constructed and furnish the test reports to the Engineering Department for use in determining a preliminary structural design of the roadbed. Tests and pavement structural design will be made by the Engineering Department after the payment of the inspection fee.

c. Thickness of Base Material and Surfacing . In no case shall the thickness of the base material be less than five-tenths (5/10) of one (1') foot, nor shall the thickness of asphalt concrete surfacing be less than fifteen-hundredths (15/100) of a foot.

d. Crown . The pavement crown and geometric design of the street cross-section shall be shown and dimensioned on the improvement plans, and shall conform to accepted design standards. The minimum cross-slope shall be two (2%) percent. On street grades over six (6%) percent, a five (5%) percent cross-slope shall be provided adjacent to the curb and gutter for a distance of not less than ten (10') feet from the face of the curb, reduction of which may be approved by the Engineering Department. Crown requirements are waived for private roads.

31-22.5 Street Trees. ¶

a. Removal . All trees conflicting with the grading, utilities, or other improvements, or overhanging the sidewalk or pavement so as to form a nuisance or hazard, shall be removed or trimmed to eliminate such nuisance or hazard.

b. Approval of Species and Planting . Trees to be planted along the street within the right-of-way shall be of such species and be planted in such locations as may be approved by the Engineering Department.

c. Encroachment Permit . An encroachment permit shall be obtained from the Engineering Department for street tree planting.