February 19, 2009

How parking rules make cities less walkable

  • Where cars dominate, walkers are discouraged. It’s time for planners to embrace new ways to handle development.
    CREÄ Affiliates


    “Walkability” appears to be on the agenda of many cities.

    However, if you are a small town or at the outskirts of a large metropolitan area, you have a whole host of regulations, standards, code, criteria and possibly public opinion that allow you to build anything but walkable communities. One challenge standing in the way of walkability is code-specified parking standards.

    For many cities, parking standards are based on a value system that revels in the single-occupancy vehicle, or the world of drive-alone commuters. This system responds to the belief that more than 95 percent of employees or customers will be driving alone.

    When shops and businesses are placed in newly developing areas with limited housing or transit services, this fact is true. Everyone has to drive to get to work, shops or schools.

    Image courtesy of CREÄ Affiliates
    Suburban developments are often surrounded by a sea of parking, thanks to code requirements. For example, this five-story building has a 1,100-square-foot footprint. Each residential unit is assigned two parking spaces, for a total of 3,000 square feet of pavement.

    However, when buildings are placed in urban growth areas that are expected to eventually merge with adjacent municipalities, or are located within city limits, there is a strong likelihood that such high parking standards could eventually prove to be excessive and burdensome.

    No-win parking

    Having excessive parking standards is a no-win situation: They increase the developer’s project costs; add to the building owner’s costs, thanks to larger repaving areas and more stormwater runoff; reflect more heat off the pavement; and diminish the experience of walking to the building because of the barren, unattractive surroundings.

    If every parking lot is overdesigned as such, buildings are separated from one another to such an extent that the public sidewalks are unattractive for walking. Long stretches of parking lot edges are interspersed with short sections of buildings.

    Lately, more attentive design of parking lot edges has improved this walking experience somewhat. However, the fact remains that most likely these environments draw very few pedestrians.

    Seas of pavement

    Parking standards are specified either as a ratio of built square footage (such as two spaces per 1,000 square feet of development), or as a ratio of the number of dwelling units (for instance, 1.13 spaces per unit). Each parking space is presumed to require about 300 square feet (if one includes the aisle between the rows of parking).

    Therefore, where parking standards for commercial development vary from two to five spaces per 1,000 square feet of commercial area, parking can take up 600 to 1,500 square feet for every 1,000 feet of built-up area. So it’s not surprising to find small commercial developments that are surrounded by a sea of parking in more suburban or rural locations.

    In multifamily residential areas, the ratio is typically between 0.7 to two spaces per unit. If these are small units — say, 800 square feet — then parking can take as much as an additional 210 square feet (or another 25 percent) per unit. For larger two-bedroom units of an average of 1,100 square feet, each unit could be required to build 600 square feet of parking. That is a ratio range of 1-to-4 to 1-to-1.8.

    If structures are multistory, then the proportion of land dedicated to parking increases exponentially compared with the amount of land covered by the building. If market economics allows for larger or more buildings on a site, the solution is to place the parking underground, which increases the cost of constructing a parking space by a factor of six to 10.

    Walkable attributes

    Walkable environments have very particular features that contribute to their frequent use. These may not be apparent to someone who isn’t an urban designer, yet research has shown each of these contribute to an active and safe pedestrian environment:

    • activities (a variety of things to do, see and engage in at intervals of roughly 20 to 30 feet);

    • visual interest (a variety of things, textures and lighting);

    • gathering spots (places where one can visit with others without inconveniencing other walkers);

    • few vehicular conflicts (few and narrow driveway cuts, well-marked pedestrian crossings over roads, frequent opportunities for walkers to cut through blocks, and so on);

    • intermittent shade (either from adjoining buildings or well-placed landscaping); and

    • safety (many uses looking over into the street, people sitting or vending along the sidewalk, walkable surfaces, lighting and sidewalk ramps).

    Handling traffic

    The suburban low-density development described earlier fails to deliver on most of the criteria described above.

    Other than allowing for designed spaces to encourage pedestrians to socialize and the possibility of good lighting, ramp design and shade, suburban sidewalks are not activated with many businesses, buildings, people, public viewing opportunities or vendors. This is compounded by frequent driveways that cut across pedestrian paths and few mid-block paths that encourage shortcuts and easy flow of pedestrian traffic.

    Creating successful mixed-use urban centers will require other ways to handle the traffic potentially generated by commercial or mixed-use developments.

    Some of these are reduced parking standards (complemented with a maximum parking requirement); increased transit or non-motorized vehicular connections (for bikes, Segways, scooters, skateboards, pedestrians); policies that encourage shared parking between two or more adjacent properties; carpooling or vanpooling incentives, including free dedicated parking stalls; transit demand-management strategies (such as flexible hours, staggered work hours, telecommuting and so on); and centralized district parking or more mixed-use dense development that places most conveniences within walking distance.

    Smart parking strategies align with walkable communities, affordable housing, and energy-efficient and green development. It is time that cities review their parking strategies to see how they can be retooled. This could be considered one of the early steps to take to creating walkable sustainable cities.

    Anindita Mitra is the founder of CREÄ Affiliates, which offers sustainable planning and design services. She is the sustainability planning advisor for the Municipal Research Services Center, co-chair of APA Washington’s Climate and Sustainability Initiative and the president of the Community Indicators Consortium.

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