Improved Parking Facility Siting and Design
The design of parking facilities should consider a number of factors including: ecological context, site location, materials, access, aesthetics, landscaping, and stormwater treatment.
The following are four best management practices that should be employed in designing parking areas (source: Massachusetts Smart Growth / Smart Energy Toolkit, 2006):
1. Ensure that vehicles are not the dominant feature
Parking should be located in the rear or to the side of buildings. Rear or side building parking enhances the streetscape appeal and removes the physical and physiological pedestrian barrier created by parking in the front.
On-street parking is encouraged. It contributes to a pedestrian friendly environment by creating a buffer between the street and the sidewalk.
Off-street, surface parking facilities that are next to residences or public streets should be screened with a continuous landscape, attractive fencing or a walled buffer.
Large expanses of parking should be broken up with landscaped islands and planted dividers.
2. Minimize unnecessary impervious surface coverage
This step can be accomplished by first maximizing on-street parking where possible. The three types of on-street parking are parallel, head-on, and angled.
In off-street parking facilities, stall dimensions can be minimized and smaller stalls can be allocated for compact cars.
Alternative pavers that allow water to pass through can create significant reduction in stormwater runoff. Alternatives includes gravel, cobble, wood mulch, brick, grass pavers,turf blocks, natural stone, pervious concrete, and porous asphalt.
Maximizing on-street parking through parallel and angled parking
3. Utilize Low Impact Development Techniques
Low Impact Development (LID) techniques can control the quality and quantity of stormwater runoff generated from a parking facility. A few example of LID techniques include:3. Utilize Low Impact Development techniques
Open sections that encourage sheet flow to open channels where pollutants are removed through infiltration and natural filtering prior to discharge, as opposed to the traditional curb and gutter methods.
Vegetative swales (see photo to the right) direct stormwater into shallow bioretention areas that temporarily detain the water to allow for partial infiltration while filtering the remaining stormwater before it is discharged into waterways.
Native plants should be used throughout the design of parking facilities because they are well adapted to the surrounding environment and typically have a greater life-cycle cost benefit. Native plants typically outperform many non-native plantings because of their deep root system, which quickly stabilizes the soils and encourages the infiltration of stormwater runoff.
4. Create a comfortable environment for pedestrians
Towns can use traffic calming measures such as marked or raised cross walks, speed bumps, chokers, and medians to slow traffic down in areas where pedestrian and vehicular traffic cross.
Parking lots should be well lit to create a safe environment and should use low-angle,cut-off fixtures to better direct light where needed and avoid glare or lighting spill over.