Municipal Design Standards Part 3 – Driveways

3.01 APPROVALS AND PERMITS

A. An access permit must be obtained before driveway construction or reconstruction not associated with the construction of a new house or business for which a building permit has been obtained. However, the standards set forth in this document apply to all driveway construction. A sketch with dimensions shall be submitted showing the driveway in relation to intersections, side lot lines and other driveways.

B. A permit must be obtained from the Iowa Department of Transportation before placing a driveway within any state highway right-of-way.

3.02 TRAFFIC CONTROL

A. The contractor doing the work is responsible for all traffic control and work site safety. If construction activities extend onto the street, traffic control shall meet the standards for Work Zone Traffic Control defined in the current edition of the “Manual on Uniform Traffic Control Devices.” Traffic control plans may be required.

B. The contractor shall provide adequate lighted barricades and/or fencing to protect pedestrians.

3.03 DRIVEWAY MATERIAL, THICKNESS AND FINISH:

A. The driveway slab extending from the street to private property shall be constructed of Portland cement concrete conforming to the specifications of the Iowa Department of Transportation C-3 or M-3 mixes. Maximum slump shall be 3 inches. The concrete driveway slab shall be a minimum of 6 inches thick.

B. Driveways shall have ½-inch preformed expansion joint material at the front and back of sidewalk. Driveways across from “T” intersections shall have one-inch pre-formed expansion joint material at the front and back of the sidewalk.

C. The finish shall be a broom finish or astroturf drag.

D. Apply curing compound immediately following finishing operations or cure with moist burlap for not less than 24 hours. Curing compound on driveways is recommended (not required).

3.04 CURB REMOVAL AND JOINT AT PAVEMENT:

A. Curb drops shall be constructed as detailed in Figure 3.1A and 3.1B.

B. Curb grinding is preferred for driveway connection. Grinding shall consist of sawcutting the back of curb and milling the curb with a milling machine to provide a smooth uniform joint between the curb line and the driveway apron.

3.05 GENERAL CONDITIONS FOR ALL CLASSIFICATIONS OF DRIVEWAYS:

A. There shall be a minimum of twenty (20) feet between the end of the radius of a street intersection and the beginning of a driveway curb cut as measured at the curb line in all instances. Additional distance between the radius of a street intersection and the beginning of a driveway curb cut may be required by the City Engineer where deemed necessary because of high traffic volumes or other safety concerns.

B. A six (6) foot minimum distance between curb cuts at the curb line will be required.

C. The curb return shall not be constructed closer than three (3) feet to the side property line extended.

3.06 SINGLE FAMILY (Figure 3.2):

A. One driveway with maximum dimensions of twenty-four (24) feet measured at the street side of the sidewalk and thirty (30) feet at the curb line will be allowed.

B. A maximum of two driveways per property will be allowed, regardless of single or double frontage (regular or corner lot).

C. If two driveways are desired on a single frontage lot, two driveways with maximum dimensions of twelve (12) feet measured at the street side of the sidewalk and eighteen (18) feet at the curb line will be allowed.

D. If two driveways are desired on a double frontage (corner) lot, one on each frontage, one driveway with maximum dimensions of twenty-four (24) feet measured at the street side of the sidewalk and thirty (30) feet at the curb line and one driveway with maximum dimensions of twelve (12) feet measured at the street side of the sidewalk and eighteen (18) feet at the curb line will be allowed. The major driveway is required to be located on the lower classified street.

E. Shared driveways for adjacent single-family residences are encouraged and in some instances may be required. To promote this goal, shared driveway maximum widths of thirty (30) feet at the street side of the sidewalk and thirty-six (36) feet at the curb line will be allowed.

F. Sections 3.05 B and 3.05 C may be varied by the City Engineer in certain instances in the existing developed areas of the City, as necessary.

3.07 TWO-FAMILY RESIDENCES (Figure 3.3):

A. A maximum of one driveway per dwelling unit will be allowed, regardless of single or double frontage (regular or corner lot).

B. One driveway per dwelling unit with maximum dimensions of twenty-four (24) feet measured at the street side of the sidewalk and thirty (30) feet at the curb line will be allowed, except as noted in 3.06 F.

C. If garages are constructed on the common lot line, a single driveway with maximum widths of thirty (30) feet at the street side of the sidewalk and thirty-six (36) feet at the curb line will be allowed.

D. Secs. 3.05 B and 3.05 C may be varied by the City Engineer in certain instances in the existing developed areas of the city, as necessary.

3.08 ALL OTHER DRIVEWAYS EXCEPT SINGLE OR TWO FAMILY RESIDENCES:

A. Single Frontage (Figure 3.4)

1. One driveway with maximum dimensions of thirty-four (34) feet measured at the street side of the sidewalk and forty-two (42) feet at the curb line will be allowed.

2. If two driveways are desired, two driveways with maximum dimensions of twenty-four (24) feet measured at the street side of the sidewalk and thirty-two (32) feet at the curb line will be allowed.

3. If the single frontage length is greater than or equal to one hundred and fifty (150) feet, two driveways with maximum dimensions of thirty-four (34) feet measured at the street side of the sidewalk and forty-two (42) feet at the curb line will be allowed.

B. Corner Lots (Figure 3.5)

1. On corner lots, driveways shall be constructed as far away from the intersection as possible and still remain upon the property. In no case shall there be less than twenty (20) feet between the end of the radius of a street intersection and the beginning of a driveway curb cut as measured at the curb line.

2. In no instance shall more than three driveways be allow on a double frontage property with no more than two on any single frontage.

3. One driveway per frontage with maximum dimensions of thirty-four (34) feet measured at the street side of the sidewalk and forty-two (42) feet at the curb line will be allowed.

4. If one frontage length is greater than or equal to one hundred and fifty (150) feet, two driveways with maximum dimensions of thirty-four (34) feet measured at the street side of the sidewalk and forty-two (42) feet at the curb line will be allowed on the longer frontage.

3.09 STATE HIGHWAY AND INDUSTRIAL AREAS (NON-RESIDENTIAL) (Figure 3.6):

A. Type A drives are for high traffic volume, joint or common property driveways requiring protection for left turn movements. Type A drives shall be 45 feet wide at the property or sidewalk line. This width contains one 16-foot lane in a 4-foot painted or raised median and two 12-foot lanes out.

B. Type B drives are for high traffic volume, joint or common property driveways. Type B drives shall be 41 feet wide at the property or sidewalk line. This width contains one 16-foot lane in and two 12-foot lanes out.

C. Type C drives are for lower volume single property driveways. Type C drives shall be 28 feet wide at the property or sidewalk line. This width contains one 14-foot lane in and one 14-foot lane out.

D. The maximum radius for all driveways is 25 feet.

3.10 DOUBLE FRONTAGE LOTS – FRONT AND BACK:

A. Each frontage of lots with frontage on two parallel streets shall comply with the applicable standards for single frontage lots contained in Sections 3.06, 3.07 and 3.08.

B. Some subdivisions may prohibit access onto the higher classification street. Check the subdivider’s agreement in each case.