9.8

9.8.2 Parking Lot Location and Design Considerations

Parking areas shall be designed and located to provide convenience and safety with minimum negative visual impact. The guidelines shall be followed when locating and designing a parking lot intended for use by automobiles and small trucks. When parking lots must accommodate circulation by medium-to-large-sized trucks, including tractor-trainer units, all dimensional criteria must be evaluated and increased accordingly. The following design considerations are intended to primarily regulate parking for non-organizational vehicles in all zones.

utilize shared parking lots

parking lots shall have landscaped islands

Parking lots should be located to maximize sharing with other related facilities and pedestrian circulation in lieu of vehicular transportation.

Whenever possible, parking lots should be designed as a series of smaller lots rather than as large, unbroken areas. The smaller parking lots enhance the visual environment by increasing the percent of landscaped area to paved area and allow more conformance to natural topography.

Parking lot layouts that promote cross-traffic between parallel streets should be avoided for safety reasons.

Motorcycle parking should be consolidated and segregated from automobile parking.

Drainage water from parking lots should be directed to adjacent landscaped areas to maximize rainfall and snowmelt benefits. In some cases, small retention ponds may be necessary to accommodate runoff from larger paved areas. A principal factor in parking lot grading shall be to provide positive drainage away from buildings and to prevent ponding of water on pavement surfaces. LID strategries such as bio retention swales, snow storage, and storm water structures shall be included in the parking lot design.

Permeable pavement should be considered in all parking lot design if applicable.

provide a defined pedestrian path through the parking lot to lead people to the facility

utilize 90 degree parking spaces

provide islands at the end of all parking rows

Parking lots should be separated from buildings by a buffer area to provide space for pedestrian access and landscaping.

Locate parking lots between and behind buildings to reduce the visual impact from the circulation system and increase pedestrian access from walkway systems.

Parking lots should be arranged for safe, efficient travel from vehicles to the buildings. The lot design should emphasize building entries by the alignment of landscape median/pedestrian paths upon each main entry.

Parking lots must be located to accommodate the landscape screening and parking lot trees referenced in the recommendations.

Locate parking lots on relatively level areas to avoid excessive cut and fill. Parking lots must be terraced to accommodate hillside locations with a minimum of cut and fill earth-moving operations. Where practical, incorporate existing topography and vegetation into the parking lot design to minimize site disturbance.

Two-way traffic aisles and 90 degree spaces are to be used as a standard. If required by site limitations or high rate of turnover, 60 degree spaces may be used with one-way traffic aisles. Use only one orientation in a parking lot to avoid potential confusion and conflicts.

Parking space dimensions shall be nine feet (9') by 16 feet (16') where vehicle overhang is permitted, and nine feet (9') by eighteen feet (18') without an overhang. Aisles and access lanes shall be no less than twenty-four feet (24') wide. Handicapped spaces shall meet requirements set forth by the ADA.

Dead-end parking lots shall be avoided for lots exceeding twenty (20) spaces. If additional access (ingress/egress) drives cannot be provided for larger lots, convenient interior circulation should allow for easy maneuvering of vehicles. Generally, two (2) access drives shall be provided for lots exceeding twenty (20) spaces.

Parking lot edges shall be set back a minimum distance from adjacent streets as follows: Twenty Five feet (25’) when adjacent to primary streets, Twenty feet (20’) when adjacent to secondary streets, and Fifteen feet (15’) when adjacent to tertiary streets. The required distance shall be measured from the face of the curb at the street to the face of the curb at the parking lot.

The perimeter edges of all parking lots, access drives, and interior "Islands" and "peninsulas" shall be physically separated from adjacent surfaces by a continuous concrete curb with integral gutter. The curb shall have a vertical face (barrier) configuration with a minimum height of six inches (6"). The use of "rolled" or similar type curbs shall not be used because they permit uncontrolled vehicular access to adjacent landscaped areas. LID strategies shall be incorporated into the overall curb and gutter design and layout.

All parking spaces and pedestrian crosswalks shall be marked with white stripes of paint or applied vinyl coatings. Red or yellow markings shall be used for safety purposes and kept to a minimum. All lines shall be four inches (4") wide. Pedestrian crosswalks in parking areas may also be identified with a change in paving material.

define parking lot edges and parking spaces

Access roads serving parking lots may be either two-way or one-way. For two-way access roads, the minimum width shall be a distance of twenty-four feet (24') measured from face of curb to face of curb. One-way traffic access road width shall be a minimum distance of fifteen feet (15') measured from face of curb to face of curb. Access to parking lots or the throat length (distance between the adjacent roadway and the point internally where drivers are presented with conflicts in the parking lot) shall be based on the type of facility being serviced by the access road. For instance, the throat length for a shoppette/video store/fast food restaurant shall be shorter than the throat length accessing a PX.
Access roads shall be separated from intersections by a minimum distance of: one hundred feet (100') along primary streets; seventy-five feet (75') along secondary streets; and fifty feet (50') along tertiary streets to minimize conflicts with vehicles turning at the intersection and those turning onto the access road. Access roadways shall be finished by application of an all-weather driving surface of hot asphalt mix or concrete pavement over flexible base capable of supporting a design wheel load of 18,000 pounds (GVW 80,000 minimum) in conformance with the pavement design criteria manuals. The design is to be prepared and certified by a registered engineer.
Provide planting areas at the ends of all rows of parking spaces. Provide islands with deciduous trees within the main parking lot to soften the visual expanse of the parking lot and to provide shade and/or wind breaks.

Use natural topography and existing trees to visually screen parking areas from adjacent facilities and other parking bays.

Design parking lots to preserve significant existing trees. Provide a planting area around the tree that is large enough to allow water to the root system.

Parking lots should be paved with concrete, asphalt, permeable pavement materials, or other paving material.
Dumpsters are not to be randomly placed on pavement within parking lots. Dumpsters will be located off parking lots, but adjacent to them, in a location that will easily accommodate pick-up by a large disposal vehicle.

Parking structures, both below grade and above grade, provide for greater parking capacity in densely developed areas where available land is scarce. Parking structures are expensive, but they provide a number of benefits including efficient land use, reduced visual impact, and protection of vehicles from inclement weather. If parking structures are built, they shall be designed to meet antiterrorism requirements.