Placemaking nurtures a sense of personal ownership and community pride in public spaces that can lead to increased social cohesion and a stronger sense of local identity. I’ve written about translating qualitative place elements into measurable data. Walkability, building engagement, and character and comfort are three qualities of a great place, and each deserves its own blog post.
Quantifying big ideas
Walkability measures the level of connectivity and integrity of the urban fabric. Walkability is often used as an abstract term to refer to the level of “friendliness” or comfort for walking in a particular neighborhood.
Over the last twenty years, it’s shifted from a planning department's dream to a traffic engineering department's reality. Whether or not infrastructure professionals understand that walking is a fundamental mode of transportation is beside the point. Public agencies have embraced the concept as a worthy goal in community planning and design.
In mathematical terms, a walkability score can be quantified as the sum of connectivity and enclosure.
Connectivity measures how easy it is to walk from one intersection to another. The length of the block is the key metric. As easy as it sounds, it’s one of the most important and overlooked elements of walkability.
Smaller, compact blocks make for a better pedestrian experience. So a long block between intersections, such as a “superblock” in front of a Home Depot or Target shopping center, is going to have a lower connectivity score than a quaint downtown block.
I recommend using the following walkability criteria to measure block lengths:
High performer (a great place) = less than 260 feet between intersections
Neutral performer = 260 - 328 feet between intersections
Low performer = more than 328 feet between intersections
Connectivity scores are very straightforward and can easily be calculated from online maps or GIS tools.
Enclosure measures how enclosed a space is using building frontage and setbacks as key metrics.
As a pedestrian, it feels better to walk in a place with buildings framing the street. Consider two short blocks that have identical connectivity scores. One with storefronts or homes will have a higher enclosure score than a block with vacant land or a surface parking lot. Buildings up to the street frame a street in a way that’s comforting for people. Psychological studies have shown that people prefer having edges along a corridor. It’s soothing.
Calculating enclosure takes a bit more effort, because it’s the product of multiplying a building frontage score by a building setback score.
Building frontage score is the percentage of a block with building frontages. For example, if the total block is 300 feet from intersection to intersection, and the total linear feet of building frontage is 150 feet, then the building frontage score is 50 percent. I recommend the following ranking methodology:
Low quality = under 40% building frontage
Fair quality = between 40%-60% of building frontage
Moderate quality = between 60%-80% of frontage
High quality = 80% or greater of building frontage
Building setback score is the average of each building setback from the street along an entire block face. I recommend using the following setback criteria:
Strong relationship (a great place!) = less than 25 feet
Moderate relationship = 25 - 45 feet
Weak relationship = more than 45 feet
Once you’ve calculated connectivity and enclosure, simply add the two for a walkability score.
Why your math is so important
To put it mildly, walkability is a pretty big deal. It’s an indicator of public health, environmental health, economic health, and social health.
People naturally walk more when it’s convenient and safe. Regular walking plays a direct role in reducing chronic diseases. It’s also been shown to reduce depression and anxiety.
More walking means less driving, and that’s great for the environment. Walkability isn’t a synonym for a high-rise, gritty city; it can be full of green spaces, trees, and cleaner air than a car-clogged alternative.
When people can walk to a local business, they’re more inclined to keep their money in the local economy. Business loves foot traffic.
Walkable neighborhoods have more opportunities for chance encounters as well as designated places to meet and connect with each other. This sense of belonging is part of why we work so hard to design for the fundamental mode of transportation—walking.