2019 Design Standards Amendments

Table 5L-4.07 Maximum Driveway Widths (6) Zoning District Frontage Driveway Width Number Lanes and Medians Type @ @ Allowed In Out Out Median Sidewalk Curb Left Right Note 2 Single Family Single 24’ 30’ 1 Single 12’ 18’ 2 max. Shared 30’ 36’ 1 Double (1) 24’ 30’ 1 and 12’ 18’ 1 Two Family Separate 24’ 30’ 1/unit Common 30’ 36’ 1 All other Single 34’ 42’ 1/ Lot Residential Single 24’ 32’ 2/Lot max. >150 feet 34’ 42’ 2/Lot Double 34’ 42’ 3 max. Non-Residential Driveway and Industrial Type (4) (Shared Driveway) “A” 45’ (3) 1 16’ 12’ 12’ 4’ (Shared Driveway) “B” 41’ (3) 1 16’ 12’ 12’ Single Driveway “C” 28’ (3) 1 14 1-14’ lane out State Highway (5) (1) For corner lot, major Driveway is required to be on the lower classified roadway. (2). Median may be painted or raised with curb. (3) Special design, radius returns may be required. (4) Driveway Type generally follows IDOT Iowa Primary Highway Access Management Policy. (5) Entrance design governed by IDOT Iowa Primary Highway Access Management Policy. (6) Distances may be varied by the City Engineer in certain instances in the existing developed areas of the City, as necessary. Chapter 6 Geotechnical 6E-1 G. Add the following subsection: J. Other Jurisdictional Requirements All roadways, streets, alleys shall be designed with engineered subgrade. As a minimum, the top 6- inches of the subgrade shall be scarified and re-compacted to 95% standard proctor density. Additional compaction may be required based on soil conditions and expected traffic volumes. Soil amendment may also be required. 6F-1 J. Add the following subsection: J. Other Jurisdictional Requirements All paved roadways, streets, alleys and driveways shall be designed with either Granular Subbase (IDOT Gradations 12) or Modified Subbase (IDOT Gradation14) with a minimum thickness of 6- inches. Additional thickness may be required based on soil conditions and expected traffic volumes. 6G-1 H. Add the following subsection: H. Other Jurisdictional Requirements All roadways, streets, and alleys shall be designed with subsurface drainage systems. Chapter 7 Erosion and Sediment Control No amendments 14