Parking

Article

Although most transportation research, published articles, and popular discussion focus on the movement of motor vehicles through roads and intersections, cars actually sit in parking spaces 95 percent of the time. In many urbanized areas, parking assumes 20-40 percent of the land surface area.

The design and location of parking is one of the most important elements of great streets. The quantity, location, management, cost, and design of parking depend heavily on the adjacent land use the parking is serving. For example, parking design in downtown areas is very different than parking at a suburban office complex. Still, there are several parking principles that permeate all land uses.

Ensure on-street parking. On-street parking is the most valuable type of parking, especially in downtown areas, for several reasons:

• It creates a physical and psychological buffer between pedestrians on the sidewalk and moving traffic.
• It presents the best access to the front door of retail, residential, and commercial destinations.
• It limits the need for off-street parking facilities. Off-site parking facilities use valuable land, require additional curb cuts through the pedestrian realm for access, and present challenges to creating good urban design. Additionally, in urban areas, off-street parking facilities can be extremely expensive.
• On a per space basis, on-street parking takes up less land area than other forms of parking because the ramps, driveways, and aisles needed in parking lots and structures are absorbed by travel lanes themselves.

Place parking behind buildings. Fronting streets with buildings (as opposed to parking) creates a more interesting, pedestrian-friendly environment. Locating parking behind buildings also allows driveways/access points to be placed on lower volume side streets, presumably with fewer pedestrians. Placing driveways (including those to parking lots) on side streets creates a more continuous pedestrian frontage, reduces the potential for pedestrian-motor vehicle conflicts, and eliminates mid-block left hand turning movements on the higher volume street - a leading cause of mid-block congestion.

Encourage shared parking. Peak parking demand for adjacent land uses often occurs at different times of the day. For example, a bank and a neighboring movie theater could feasibly share spaces as their parking demand peaks at different times. Although such arrangements are more common in mixed used districts, shared parking can be implemented in all place types. Shared parking decreases the need for off-street parking spaces and lots, which imparts many of the benefits mentioned above. See the Urban Land Institute’s Shared Parking (Smith. Shared Parking, Second Edition. ULI and the International Council of Shopping Centers. 2005) for more information about shared parking.

Source: ADAAG

Provide handicapped parking. Federal law requires that handicapped parking be provided in all designated parking areas. The Americans with Disabilities Act (ADA) sets guidelines for handicapped parking requirements for all new construction. The minimum number of required handicapped spaces is based on the total number of spaces in the parking facility, as outlined in the figure at right.

The location of these spaces is also regulated, as explained below in the ADA Accessibility Guidelines:

“Accessible parking spaces serving a particular building shall be located on the shortest route of travel from adjacent parking to an accessible entrance” (ADAAG 4.6.2).

Although there are established national standards, individual municipalities often set their own standards for handicapped parking. A 1990 study of retail shopping centers found that the number of handicap spaces in commercial areas varied between 0.7% and 2.0% of the total parking supply (Weant and Levineson. Parking Spaces. McGraw Hill. 1999).

Include bicycle parking. Although automobiles typically come to mind when parking is mentioned, great streets have provisions for all modes, including adequate and secure bicycle parking. There are no national standards for bicycle parking, and local requirements vary widely. One of the most convenient methods for establishing appropriate bike parking design is to view the ordinances of municipalities with high bike mode shares. The city of Madison, Wisconsin, for example, provides excellent guidelines on the appropriate quantity, location, and design of bike parking. The city of Portland, Oregon also has an excellent web page with guidelines for installing bicycle parking. For more information on bicycle parking, see Bicycles .

Minimize supply. Parking is often oversupplied, which creates a number of design challenges. A 2003 study of 42 parking lots during the holiday season found that the average occupancy was less than half (Gould. “Parking: When Less is More.” Transportation Planning, Vol.28, No.1. Transportation Planning Division, APA. Winter 2003).

Source: City of Seattle

Retail shopping centers with massive parking facilities that are rarely (if ever) full are a common sight in most communities. Parking is oversupplied because the minimum parking requirements for residential and commercial development is often set at the annual maximum expected demand, leaving excess parking for much of the year.

Ensure delivery parking. Delivery parking must be provided in most, if not all, place types, but is particularly important in areas with a high concentration of retail shops and restaurants. Alleys are ideal locations for temporary truck parking, allowing back door delivery access away from customer parking and entrances. When alley use is not feasible, special loading zones can be designated. The image at right is an example of signage used in a loading/unloading zone.

Use low-impact design in parking lot construction. The impervious surface of parking lots has one of the most significant impacts on stream quality, because large volumes of rainwater flow off the parking lot and directly into local streams. The parking lot runoff also contains pollutants that typically flow with the stormwater directly to the streams.

Using pervious paving (paving blocks made of pervious concrete) and including swales to capture and slow rainwater are two strategies that can be easily implemented to reduce the negative impact of parking lots. See the Stormwater section of this guide for more information.

Parking for Mixed-Use Districts:

Implement Shared Parking. Shared parking is particularly relevant for mixed use districts and small town downtowns. The benefits to implementing shared parking include:

• Reduction of land devoted to parking;
• Reduction of development costs;
• Concentration of access points; and
• Potential to redevelop areas where on-site parking is not feasible.

While many jurisdictions allow for shared parking, developers are often hesitant to take advantage of the opportunity, due to the following potential challenges:

• Timing of new developments is not conducive to providing shared opportunities;
• Allowable walk distance between the land use and the shared parking facility is set too short by local governments, limiting opportunities;
• Developers may be concerned about delays resulting from joint development agreements;
• Land use types may change, affecting parking availability for all parties; and
• Financers may perceive additional risk and lack of control over undedicated parking spaces.

Aggregate Parking into Structures. A subset of shared parking, aggregating parking into structures has several benefits:

• Reduction of parking costs, as large facilities are cheaper to build on a per space basis;
• Eliminates the need for additional access points;
• Encourages a “park once environment” where people can access stores on foot;
• Allows for public/ private partnerships of parking structure financing;
• Creates a convenient, single location where patrons will always be able to find a space (as opposed to multiple, smaller satellite spaces); and
• Creates opportunities to switch to a paid parking environment.

Design appropriate on-street spaces. According to the ITE’s Context Sensitive Solutions in Designing Major Urban Thoroughfares:

• 

  Credit: Dan Burden

  “On-street parking should primarily be parallel parking on urban arterials, boulevards, and avenues. Angled parking may be used on low-volume commercially-oriented collector avenues and streets, primarily those serving as main streets” (Context Sensitive Solutions in Designing Major Urban Thoroughfares, 2006, p.131). Traditional, head-in angled parking is discouraged on streets with bicycle lanes located between the travel lane and the parking due to the poor visibibility by cars backing out. However, head-in angled parking may be appropriate when bicycles share the travel lane with cars. For more information on bicycle facilities, see Bicycles.

• Back-in (or tail-in) diagonal parking affords drivers greater visibility when leaving a parking space, and should therefore be considered in downtowns and mixed use districts. Credit: Dan Burden The images at right show how back-in parking can work well in mixed use districts and areas with heavy bicycle traffic. Back-in parking must be designed so that vehicle overhang does not encroach on the pedestrian walkway.

• Generally, bike lanes should not be included on streets with parallel parking. Bike lanes increase the necessary right of way of the street and are not usually necessary on low-volume, mixed traffic streets.
• The appropriate width of angled parking depends on the angle of the spaces. The chart at right outlines the proper dimensions for parking spots at various angles.

Source: Dimensions of Parking

Implement Paid Parking. Businesses often claim that parking in the business area is inadequate. The best strategy to increase the available parking supply in downtowns and mixed-use districts is to switch to paid parking. Although initial resistance is common, paid parking has proven successful in a multitude of districts.

Benefits of paid on-street parking spaces include:

• 

  Credit: Charlier Associates, Inc.

  Employees will be discouraged from using high-value spaces close to business front doors.

• Prices can be set high enough to ensure the availability of spots, but low enough to not discourage use.
• Money generated can be used to improve the business district, placing electric utilities underground, street sweeping, etc.
• The less convenient parking structures can remain free, subsidized by the more convenient, paid on-street spaces.

Resources

PDFs:

• Madison Bicycle Parking Ordinance
• Portland Shared Parking Guidelines - A compendium of benefits and challenges, including developer interview responses.
• Portland Model Ordinance

Links:

• ADA parking requirements
• Portland bicycle parking guidelines