Smart Parking

In Brief: Parking standards and strategies play an important role in determining the quality of the built environment in cities and towns of all scales. Currently, many municipalities rely on antiquated parking standards that result in an overabundance of parking at the costs of community character and vitality, an increased "urban heat island effect", loss of recharge to drinking water supplies, and more polluted runoff. Smart parking approaches can address these issues through a variety of techniques including: tailoring standards, managing demand, and improving parking facility design. A well planned and executed parking program is essential to establishing and maintaining a human-scale environment that emphasizes parking efficiency over supply.
Busy street corner.
Source: ABL Architecture
The Problem

Large parking lot with few cars.
Current standards create "dead zones" of underutilized parking lots
Source: Behan Planning Associates

Across the country, the increased mobility and convenience provided by the car continues to encourage sprawling patterns of development. Massachusetts has been no exception as land uses within our cities and towns are becoming increasingly segregated. Consumers and residents have come to expect safe, plentiful, and easily accessible parking at home, at work, and at the store. Accommodating this growing parking demand has become a high priority for many municipalities and is frequently a major issue in the review of site developments. While the need for adequate parking is undeniable, many current standards are excessive and often disrupt a community's ability to foster an appealing, livable environment. To make matters worse, parking facilities are often poorly sited and designed.

Municipalities in Massachusetts often rely on generic, one-size-fits-all parking standards that are simple to apply and enforce, but fail to accurately reflect the particular needs of different districts. Many local variables should be considered when determining an area's parking needs, including: the mix of land uses, density, demographics, availability of transit, potential for biking or walking, and the availability of nearby parking. The use of inflexible standards often provides a surplus of parking and creates "dead zones" of empty parking lots. These wide stretches of uninterrupted asphalt can erode streetscape appeal, deter pedestrians, and seriously compromise the development potential of an individual site or neighborhood. Additionally, the negative environmental impact of impervious surface coverage is now widely recognized as a major threat to the health of our groundwater and surface water resources. While creating parking structures can reduce the problems of "dead zones" and surface runoff, the cost of constructing structured parking can be as much as five times more per space than constructing a surface parking lot. This vast difference in cost makes structured parking a difficult option to pursue, especially in suburban and rural areas that exhibit lower land costs.

A major problem with current parking standards is the source from which they are generally derived. The two most frequently used sources to determine parking standards are: 1) nearby municipalities, and 2) the Institute of Transportation Engineers (ITE). The strategy of duplicating a nearby municipality's standards often results in repeating mistakes and fails to recognize the unique elements that make each municipality's parking needs different. With regard to the standard ITE parking rates, recent examination of these standards shows that they were derived from a small number of studies located in suburban environments with high car dependency. The broad application of ITE standards to cities and towns that do not exhibit the same characteristics as suburban environments will therefore produce a surplus of parking and lots that are only full during the winter holiday season.

Introduction to Smart Parking

This section will present an overview of strategies that address the challenge of planning for parking within the context of smart growth / smart energy. The primary tools to be discussed are: tailoring parking requirements, parking management districts, shared parking, demand management techniques, and improved parking facility siting and design. The following section will discuss implementation considerations.

Tailoring Parking Requirements

One of the principal ways planners can control the over-supply of parking is by revising local zoning ordinances to achieve a more accurate reflection of the local conditions and parking demand. Rather than broadly imposing inflexible standards, local zoning ordinances can incorporate methods for reducing minimum parking requirements based on a series of local variables including: location factors, demographics, fees-in-lieu programs, and transportation demand management programs. Establishing parking maximums or area-wide caps is a different approach focused on restricting the total number of parking spaces allowed on a site or in an area. Unlike reducing minimum requirements, which provides the flexibility attractive to many developers, establishing a maximum sets an absolute limit that cannot be exceeded. Tailoring minimum requirements and establishing maximums are the two primary means for achieving increased parking efficiency.

Parking Management Districts

Parking management districts (PMD) are areas designated by a local municipality in which parking rates and supply are regulated by a municipal agency to meet the needs of the area. PMDs are typically established to encourage mixed-use developments that maximize land by easing on-site parking requirements. This approach can encourage a variety of creative solutions to address the district's parking supply and needs. The two components that drive the management of parking districts are supply management strategies and pricing policies. These components are designed to work together to boost economic development while promoting a balance among transportation options.

Shared Parking

Shared parking is the concept of utilizing parking facilities jointly among different buildings or businesses in an area to take advantage of different peak parking characteristics. Proximate businesses that exhibit different peak parking demands also present an opportunity for shared parking arrangements. For example, many business and office parking lots experience their peak during the daytime hours while restaurants and movie theaters experience their peak during the evening.

Digital parking meter.
Pricing policies can be an effective demand management measure
Source: Boston Globe

Demand Management

Another strategy for limiting parking supply is to reduce the demand for parking through a variety of measures. These strategies seek to promote alternatives to single occupancy car travel. It is possible to reduce parking demand through investments in alternative transportation, transportation demand management programs, pricing policies, and policies supportive of high-density and mixed-use development such as traditional neighborhood design or transit-oriented development.

Parking Facility Design

With the advent of auto travel in modern society, our built environment has increasingly become the domain of the car. Parking facilities have become an ever-present fixture in our urban, suburban, and rural landscape. The need for parking is evident, however, the facilities present many problems such as consumption of land and resources, contribution to water pollution, degradation of streetscape appeal, and the creation of conflicts between cars and pedestrians. All these problems present an opportunity to drastically improve the appearance, safety, and well being of our cities and towns through improved parking facility design.

Considerations for Implementing Smart Parking

There are a wide selection of smarter parking strategies available to reduce sprawl. Municipal planners must carefully consider their city or town's particular needs and circumstances before taking any action towards implementation. These strategies are by no means mutually exclusive as they can be implemented individually or in concert with each other. The following section will serve as a guide to how each of these strategies can be put into practice.

Tailoring Parking Requirements

Addressing minimum parking requirements is an important first step toward reducing the oversupply of parking. Minimum parking requirements are the traditional method municipalities use to control the amount of parking, as calculated by the ratio of the number of parking spaces required per square foot, per dwelling unit, or another measure of intensity. Zoning ordinances can be revised in their entirety or new zoning overlays can be created to allow for greater flexibility and reduced requirements based on local considerations. It is important to note that developers are often supportive of tailored minimum requirements as they can alleviate the need for large lots which reduce a site's development potential and increase overall construction costs.

While not an exhaustive list, the following variables are the most appropriate to consider when justifying decreased minimum requirements:

  • Locational Factors:  If the project is in or near an area of high density or is well served by mass transit, it can be inferred that none of the site users will be traveling by car. Consideration should also be given to the existing parking conditions and the extent to which on-street parking or nearby facilities can absorb additional demand.
  • Demographics:  The demographics of the surrounding neighborhood as well as the targeted customer and employee groups should also be considered. If the anticipated users of the site display lower levels of car ownership (often based on age or income level) then the project may require less parking.
  • Fees-in-lieu:  Municipalities can establish fees-in-lieu programs as an alternative to requiring on-site parking. If the developer agrees to pay into a parking fund then the minimum requirement can be reduced. Fees-in-lieu funds are often used to finance off-site parking facilities such as large lots or structured parking. 
  • Transportation Demand Management (TDM) Programs:  TDMs are typically employer-led programs that reduce the parking needs of employees by encouraging alternatives. If the developer commits to establishing a TDM program through a covenant during the permitting process, then the minimum requirement can be reduced.

Establishing maximum requirements or area-wide caps require different considerations. As opposed to increasing flexibility on a project-by-project basis, maximums provide a concrete restriction on an applicant's ability to expand parking facilities. This can be a very effective way to reduce the footprint of larger scale retailers that often propose far more parking than necessary. Area-wide caps go above and beyond regulation on a site-by-site basis by setting limits to the total number of parking spaces allowed within a defined district. The advantages to parking maximums and area-wide caps are that they promote better use of existing parking facilities and force businesses to encourage alternative modes of transportation. A common concern among developers is that lending institutions may be hesitant to finance a project that does not provide adequate access for consumers. Local practitioners looking to enforce parking maximums or area-wide caps may therefore want to research the standard practices of several lending institutions to help address these concerns.

Parking Management Districts

Parking Management Districts (PMDs) are designed to fit the needs of higher density, mixed-use districts with an existing or planned centralized shared parking facility. The primary regulatory tool that PMDs utilize is a parking ordinance that allows local authorities to allocate centralized parking or require centralized parking on a project-by-project basis. A PMD is regulated by a municipal agency that examines each development or re-development project within its boundaries to assess the appropriate parking approach and number of spaces required. Some of the factors that a PMD can review in the site development process include the amount, size, and appearance of on-site parking, as well as the feasibility of incorporating on-street and off-site facilities. This provides the PMD with control on a site development basis, while monitoring the overall parking needs of the district. The goal of a PMD is to find the balance between increasing opportunities for land to be developed into buildings - not parking lots - while still allowing a critical degree of car access. Within this supply management balance, a district's pricing policies are used to influence travel behavior and limit parking demand.

PMDs are funded through four major sources: parking receipts, fees in lieu, enforcement revenues, and income from investments. Funds are typically used for developing and maintaining centralized parking facilities. The result of properly administered PMDs with a centralized parking facility is the development of a "park once" environment in which residents and visitors can reach multiple destinations by parking once and walking as opposed to multiple, short car trips.

Centralized parking structure.
Centralized parking structures can be hidden to minimize their visual impact
Source: Jirsa Hedrick Associates

Shared Parking

Allowing for shared parking can greatly reduce inefficiencies in parking supply and increase flexibility for parking requirements to be met through on-street parking or off-site facilities. There are generally two means of implementing shared parking: through the local zoning ordinance or through agreements between individual property owners. Two or more different land uses that share a single lot are typically required to account for the entirety of their individual parking requirements so that the total number of parking spaces within that lot is equal to the sum of spaces required for each individual use. This often results in a significant amount of unused parking spaces. Those municipalities that have adopted shared parking provisions in their ordinances experience relatively little additional regulatory procedure, yet gain significantly more efficiency in their parking supply.

The first two items to consider when implementing shared parking are the metric for determining the time-needs of different uses and the limit on the distance shared off-site facilities can be from the use. One frequently used method to determine the amount of parking required by use is the following calculation: 1) determine the minimum amount of parking required for each land use by time period; 2) calculate the total parking required across uses for each time period; and 3) set the requirement at the maximum total across time periods.

Source: Montgomery County, Maryland

The above graphic shows the breakdown of uses by time as stipulated by the zoning ordinance in Montgomery County, Maryland. In this example the minimum requirement for shared facility is 521 spaces, as that is the maximum number required at any one time period. This is significantly less then the 710 spaces that would have been required if shared parking was not allowed.

Another method to determine shared parking is to let the parties involved decide the appropriate number of spaces. In these cases, the applicants must submit a similar analysis as the one above demonstrating the variation between peak parking times and the minimum requirement given the busiest time period of the day. When implementing shared parking, it is important to consider the long-term consequences of changes in ownership, operations, or use that may change parking demand in the future. Many ordinances require contingency plans to provide for additional parking should a change necessitate a new minimum requirement.

Demand Management

Implementing parking demand management can take a variety of forms. Investing in transit or re-zoning to support Transit-Oriented Development (TOD) or Traditional Neighborhood Design (TND) is an effective method for reducing parking demand, yet can also be a complicated, intensive planning process. The primary challenge to these strategies is the significant amount of upfront investment of funds and time that can be required. Considerations for implementing these strategies are discussed in greater detail in other modules of the Smart Growth Toolkit. The most common approaches to demand management are Transportation Demand Management (TDM) Programs and appropriate pricing policies.

TDM programs can be initiated by a municipality or a private entity and are designed to encourage alternatives to single occupancy car travel which is currently the dominant mode of transport to work. Unfortunately, free and accessible parking at work has become a baseline expectation for much of the current workforce, except in major urban centers such as Boston. To address this situation, many businesses initiate TDM programs for their employees that create incentives for choosing alternative transport options that reduce parking demand. Aside from general education of the benefits of employee-led actions such as opting for transit and car pooling, a number of specific employer-led TDM programs can be established.

  • Cash-Out Programs:  Many companies offer cash-out programs that allow employees to trade in their parking rights for the equivalent value in a cash payment. A study by the Victoria Transport Policy Institute showed that cash-out programs can reduce parking demand by 15-25%.
  • Car Sharing:  Car sharing involves financing the purchase of a car or several cars that are to be used by multiple users. Car sharing can be done at a variety of scales such as a business making available a small number of shared vehicles to its employees, or a municipality helping a car sharing company make dozens or even hundreds of cars available to the public. According to Zipcar, a successful car sharing company, each shared vehicle can replace anywhere from four to eight privately owned cars.
  • Peripheral Parking with Shared Transport:  Municipalities and employers may also choose to locate parking facilities a significant distance off-site to save money. This option may not necessarily reduce single occupancy car travel, but may shift the necessary parking spaces outside of the primary activity center. On a broader scale, this aids the development of an urban core by allowing higher densities through decreased urban parking.
  • Bicycle Facilities:  Municipalities and businesses should consider requiring bicycle parking facilities such as storage, showers, and lockers on-site. Offering employees and customers appropriate bicycle amenities can significantly reduce car travel depending on density and setting.

One of the simplest ways to reduce the demand for parking is through pricing policies that directly charge users for the cost of parking. The cost of providing parking is always realized by the consumer, whether it be through taxes, bundled with rent or purchase prices, or through a direct charge to the user. Parking pricing has been shown to reduce parking demand by 10-30% compared to un-priced parking (Victoria Transport Policy Institute). It is important to consider how pricing policies affect different demographic groups. There are a variety ways to implement pricing to achieve economic and social objectives.

  • Time-Based Pricing:  Can be implemented in on-street parking and off-street parking facilities to discourage long-term commuter parking and encourage turnover. This strategy is designed to increase economic activity by opening up parking for customers and compelling commuters to find other options. If charging for parking is not appropriate for the area, time-based parking can be implemented without a issuing a fee.
  • Vehicle Occupancy Pricing:  Can be implemented in off-street parking and can charge higher rates for solo drivers as opposed to vehicles with multiple travelers.
  • Vehicle Size Pricing: Can be implemented in off-street parking and is designed to differentiate pricing based on car size to encourage use of compact cars that use less space for parking. 

It can be difficult to implement pricing in areas where the parking is predominantly free as it can lead to a disgruntled general public and business owners. A major challenge to implementing parking pricing lies in the surrounding, uncontrolled parking facilities that will receive additional spillover from users circumventing the priced parking areas. Managing spillover can involve several strategies such as maximizing on-street parking and residential permits programs. As a general rule of thumb, a smart parking approach seeks to maximize on-street parking whenever possible to decrease demand for off-street lots. Although maximizing on-street parking has the drawback of limiting travel space within the street's right-of-way, it provides many benefits such as: convenient location in front of buildings, buffer space between cars and pedestrians, snow removal storage, traffic calming, and space for bus bulbs and corner bulbouts.

Residential permit programs are appropriate in areas that exhibit high parking demand in close proximity to residential neighborhoods. Spillover from commercial areas, employment centers, or transit stations can have a severe impact on the availability of on-street parking for residents of surrounding neighborhoods. Within Massachusetts, there are a number of municipalities that implement residential permit programs including: Boston, Cambridge, Somerville, Everett, Brookline, and Amherst. Residential permit programs can be structured to allow residents to purchase a permit that is valid within the entire municipality, or separate permits can be issued for separate neighborhoods to localize the areas in which residents can park. Typically the cost of a residential permit in Massachusetts is minimal, ranging from free to 20$, as the goal of the program is not to limit demand amongst residents but instead to accommodate residential demand through minimizing spillover.

Parking Facility Design

The sustainable design of parking facilities is a crucial component to the advancement of a smart parking approach. Facility design should account for such factors as: ecological context, site location, materials, access, aesthetics, landscaping, and stormwater treatment. There are four primary objectives to consider when designing a smart parking facility. Each objective contains a series of best practices and important considerations.

  1. Ensure that vehicles are not the dominant feature. There are several ways to ensure that parking facilities, and the vehicles within them, do not become the dominant feature of the streetscape. Parking should be located in the rear or to the side of buildings enhancing the streetscape appeal and removing the physical and physiological pedestrian barrier created by parking in the front. Signage leading drivers to rear building parking should be clear to alleviate potential frustrations. On-street parking is encouraged and should be the only parking found in the front of buildings. On-street parking also contributes to a pedestrian friendly environment by creating a buffer between the street and the sidewalk. Off-street, surface parking facilities that abut 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. In the case of structured parking, architectural standards should be enforced to integrate the appearance of the structure with surrounding buildings. Generally, the design and location of structured parking should fit within the urban fabric of the street utilizing techniques such as "wrapper uses". "Wrapping" a parking lot with active uses such as retail or other commercial uses can help maintain a vital street life and provide visual interest.

    Landscaping techniques for parking islands and dividers, Henderson, NV

    Landscaping techniques for parking islands and dividers, Henderson, NV


  2. Minimize unnecessary impervious surface coverage. The first step to minimizing impervious surface coverage is to limit off-street parking by maximizing on-street parking where possible. There are three types of on-street parking: parallel, head-on, and angled. While head-on and angled parking allow for more cars they also encroach farther into the right-of-way and can be dangerous for parked cars to back out into moving traffic. With off-street parking, minimizing stall dimensions and allocating smaller stalls for compact cars is a straightforward way to reduce lot size. Parking structures increase space efficiency compared to surface lots, however, depending on the price of land they can be cost prohibitive. Developers often receive financial incentives to build structured parking, so alternative financing methods such as District Improvement Financing (DIF) should always be investigated. Finally, the use of alternative pavers that allow water to penetrate can create a significant reduction in stormwater runoff. Alternatives to concrete and asphalt include gravel, cobble, wood mulch, brick, grass pavers, turf blocks, natural stone, pervious concrete, and porous asphalt.

    2 on-street parking examples.

    Maximizing on-street parking through parallel and angled parking


  3. Utilize Low Impact Development techniques.
    Bioretention pond.
    Bioretention ponds should be planted with appropriate native vegetation
    Low Impact Development (LID) techniques can control the quality and quantity of stormwater runoff generated from a parking facility. In regard to parking facilities, common LID techniques include: open sections, vegetative bio-swales, bioretention, and permeable pavers/porous pavement. Open sections 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 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. Selecting the proper plant material is critical to the success of these techniques. It is recommended that native plants be used throughout the design 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. The effective use of LID techniques not only reduces stormwater runoff, it can also reduce construction and maintenance costs by 25-30% compared to conventional gutter and pipe approaches (Prince George's County Department of Environmental Resources).

  4. Create a comfortable environment for pedestrians.
    Alternative paving is used to distinguish pedestrian pathway
    It is critical to approach parking design with the thought that these areas are a shared domain of cars and pedestrians. As such, the pedestrian amenities should be an integral part of parking facility design. Traffic calming elements such as marked or raised crosswalks, speed bumps, chokers, medians, and bollards can all be used on occasions where pedestrian and vehicular paths cross. Limiting curb cuts enhances the pedestrian experience by increasing space for on-street parking, creating a buffer to street traffic, increasing space for landscaping, and reducing pedestrian and vehicle conflicts. Within large parking lots, pedestrians should be provided with well marked pathways or corridors complete with alternative paving and/or raised crosswalks across vehicle paths. Parking lots should be well lit to create a safe environment and should utilize low-angle, cut-off fixtures to better direct light where needed and avoid glare or lighting spillover to abutting residences.

Financial Considerations

The costs associated with constructing and maintaining parking facilities can have a huge impact on the feasibility of a smart parking approach. The type of parking facility incorporated into a development project - whether it is a surface or structured facility - is typically decided by measuring the cost of land versus the cost of construction. The cost of constructing a parking structure can be as much as five times more per space than constructing a surface parking lot. Due to this enormous cost difference, creating structured parking in suburban and rural environments - areas that typically exhibit lower land costs - is less cost-effective than creating surface parking. A study conducted by the Victoria Transport Policy Institute concluded that structured parking typically becomes cost-effective when land prices exceed about $1 million per acre.

Without the proper financing mechanisms, suburban locations will continue to choose surface parking lots over structured parking facilities. Significant incentives for creating structured parking are needed to reach a new balance between construction costs and land costs, which will support a more efficient use of land. Strategies for relieving the high costs of structured parking exist for both privately - and publicly - owned facilities.

Privately owned parking facilities are typically financed through private banking institutions. There are various ways for developers to recoup construction expenses including: bundling parking costs into the rents and purchase prices of parking users, charging parking fees, and arranging to lease or sell space in the parking structure itself. As for publicly owned facilities, financing typically occurs through the issuance of municipal bonds. A variety of bonds exist including: general obligation bonds, special assessment bonds, revenue bonds, double-barreled obligations, and tax increment finance bonds. Municipal bonds for structured parking typically carry low interest rates due to federal, state and local exemptions. The bonds can be paid back through tax revenues or parking related revenues, such as user fees, fines and fees-in-lieu. In addition, several state funding sources assist with the construction of parking garages including the Transit Oriented Development Bond Program and the Off-Street Parking Program.