A. The geometric design of a driveway shall be governed by sound traffic engineering principles and the ability of the driveway to provide adequate access for motor vehicles and emergency service and fire apparatus in all weather conditions.

B. The following minimum standards shall be maintained:

(1) Horizontal curves shall have a minimum center-line radius of 50 feet.

(2) Vertical curves shall be flat enough to prevent the dragging of any vehicle undercarriage.

(a) For sag curves, the maximum change in grade shall not exceed 12% in a length of 10 feet.

(b) For crest curves, the maximum change in grade shall not exceed 8% in a length of 10 feet.

C. All driveways shall be designed and constructed to the following widths:

(1) Single-family residential driveways shall have a minimum width of 10 feet. Where depressed curb is utilized, the curb opening shall be a minimum of four feet wider than the driveway, but not less than 20 feet in total width. Where no curb exists, additional pavement shall be provided for turning having a radius not less than five feet or more than 1 0 feet.

(2) Commercial and industrial driveway widths shall be designed to accommodate the volume and character of vehicles entering and leaving the site. For two-way operation, the driveway shall have a minimum width of 24 feet and a maximum width of 40 feet. For one-way operation, the driveway shall have a minimum width of 20 feet and a maximum width of 34 feet. Where depressed curb is utilized, the curb opening shall be a minimum of four feet wider than the driveway. Where a curb radius is utilized, the radius shall be not less than 25 feet or more than 40 feet.

D. Maximum driveway grades shall conform to the following:

(1) Residential driveways shall be constructed at a profile grade not exceeding 15%, except that within the road right-of-way or within 25 feet of the center line of the road, whichever is greater, the grade shall not exceed 4%.

(2) Commercial or industrial driveways shall be constructed at a profile grade not exceeding 6% or 4% within 100 feet of the road right-of-way line.

E. All driveways shall intersect perpendicular to the existing road pavement or traveled way. Any curved or angular approach of the driveway for aesthetic or topographical reasons shall be accomplished outside of the road right-of-way or beyond 25 feet from the center of the existing pavement, whichever is greater.

F. All new driveways located on newly developed lots shall be designed and constructed so as to provide sufficient turning areas on site, in order that vehicles are not required to back out onto any public street. Relocated, reconstructed or altered driveways serving existing improved properties shall be required, to the greatest extent practicable, to be designed and constructed so as to provide sufficient turning areas on site in order that vehicles are not required to back out onto any public street. [Amended 4-11-2000]