What is Walkability?

A walkable neighborhood is one where you can access amenities without needing a car, and instead get around comfortably and safely on foot or bike. There's a lot of factors that go into understanding how walkable a place is.

Everyone enjoys a walkable neighborhood. This is true even if you love your car, as many Americans do. But think of the places people go and things they do when on vacation – strolling among parks, shopping, sightseeing, walking to get a drink or having dinner on a patio. Walking is pleasurable. Even Walt Disney’s famous theme park is modeled on his ideal of what Main Street, USA should be.

Walkability describes how easy it is to get to places without a car. It’s also about more than just walking. Walkable cities make it easier for disabled people to get around, with sidewalks that are accessible. Neighborhoods that are walkable also have streets with lower speed limits, making it safer to ride a bike or scooter.

Finally, walkability tends to go hand-in-hand with public transit, because it makes it possible to get to more distant parts of a city without a car.

To be clear, a neighborhood with poor walkability doesn’t mean that it’s bad. For example, you wouldn’t expect an agricultural area to have sidewalks and a subway system. Neighborhoods are designed to fit a purpose, and walkability is just one measure that a person might use to decide if a place is the right place for them. Walkability by itself doesn’t make a place good, but neighborhoods where people can drive less does come with clear health and environmental benefits.

How do you measure walkability?

There has been a lot of research into walkability, including efforts to try to measure what makes one neighborhood more walkable than another. That’s what this website is about. You can look up nearly any address in the United States, and get a detailed analysis of how walkable that neighborhood might be.

I say might be due to limitations in the data that make it impossible to exactly determine whether a neighborhood meets an individual’s idea of what walkability means. Walkability is, to some degree, subjective and can mean different things to different people. For example, if it’s important to you to be able to walk to a grocery store, this database doesn’t have that information (yet). The walkability index has information on how many retail jobs are in a neighborhood, but doesn’t have data on the exact types of businesses. It also doesn’t have data on the presence or quality of sidewalks.

Despite these limitations, we can still make strong inferences about whether a neighborhood is walkable. For example, while there isn’t sidewalk data, there is data on the speed limit of streets. Roads with a maximum speed limit of 30 mph aren’t highways, and are often residential streets with sidewalks, especially if they’re located in urban areas.

The database has dozens of data points about every neighborhood which are distilled into four major categories that make up the main Walkability Index. These are:

• Whether there is a mixture of employment and housing in the same neighborhood
• The mix of employment categories in the neighborhood
• The density of pedestrian-friendly intersections
• The distance to the nearest public transit stop

When you do a search on WalkabilityIndex.com, a score between 1 and 20 (where 20 is best) is displayed for each of these sub-categories, which together make up the main Walkability Index.

A note about the data source

Before we dive in, let’s take a look at the data source behind WalkabilityIndex.com. The National Walkability Index was produced by the US Environmental Protection Agency (EPA) with data from the Smart Location Database. All of this data is in the public domain and can be used freely. You can find out more or download the data yourself at the EPA’s page.

The EPA’s website and documentation is quite technical in nature, so WalkabilityIndex.com was designed make this information more accessible and user-friendly.

One important detail is the geographic definition of a neighborhood. The Walkability Index uses data at a granularity of the United States Census Bureau’s block group. A block group is the smallest geographic unit for which the Census Bureau publishes data, and typically encompasses an area with a population of about 600 to 3,000 people.

This definition of a neighborhood might not match what local residents think of as the boundaries of their neighborhood. That’s expected, because everyone will have a slightly different idea of what their neighborhood is. If anything, block groups are smaller than what you might think of as your neighborhood. Because of this, it’s possible that your actual experience of walkability could be different from what the index suggests because of more or fewer amenities in adjacent neighborhoods. This would be especially true if your home address is near a neighborhood boundary.

Zip codes are also commonly used by people to describe the area where they live, but they are created by yet another agency (the US Postal Service), and the boundaries of zip codes don’t line up with Census boundaries. This means that a block group could overlap with one or several zip codes. Zip codes that overlap a neighborhood are listed on our search result pages.

Despite these few limitations and caveats, the Walkability Index is a great resource that can tell you a lot about a neighborhood. Next, let’s break down the major categories that make up the index.

Category explanation: Mix of Employment and Housing

The first category is called “Mix of Employment and Housing”. In the EPA database, it’s referred to as “Employment and household entropy” – a much more technical term that we relabeled to be more user-friendly.

This is a measure of whether a neighborhood contains both jobs and occupied housing units (empty homes don’t count). A high score is given when a neighborhood has both residents and jobs in a mixture of categories. It’s called entropy in the source data because in physics entropy describes disorder and randomness in a system. In this case, a low entropy neighborhood is one that is highly ordered and homogenous, while a high entropy (less ordered) neighborhood would have a mix of lots of different services and housing.

When it comes to walkability, high entropy is good. One of the things that makes a place walkable is the presence of destinations near to where people live. A neighborhood that only contains homes doesn’t have places to which you can walk for employment or amenities. Similarly, an area with lots of retail shops and offices could actually be very walkable, but if few people live there, you may need to drive there to take advantage of it.

One limitation is that this measure only looks at job categories, and not the actual businesses that are located there. For example, imagine a neighborhood that for some reason has a hammock district with lots of stores that sells hammocks. This would show up in the data as lots of retail jobs, which would suggest easy access to grocery stores and other shops you might need on a daily basis. If the neighborhood also has jobs in other categories as well as people living there, it would score well in the Mix of Employment and Housing category. However, unless you work in hammock sales, having a lot of hammock stores wouldn’t be very helpful to most people.

This is a bit of a silly example, but it’s useful to help understand the limits of the data. That said, the Mix of Employment and Housing category will help you differentiate between neighborhoods that are purely residential or commercial.

Category explanation: Employment Diversity

The next category is employment diversity, referred to in the source data as employment entropy. It is similar to the previous category, but doesn’t consider housing.

Having jobs in a neighborhood is good for walkability, but less so if all the jobs are in the same category. Like our hammock district example, a neighborhood that contains only one type of employment is generally less walkable than one with employment in many categories. For example, if a neighborhood doesn’t have jobs in the health care or education categories, residents might be forced to drive to school or medical care.

Category explanation: Pedestrian-Oriented Intersections

Unless they’re willing to go hiking, pedestrians need streets. More specifically, they need sidewalks, but as mentioned earlier, this database doesn’t contain information on the presence or quality of sidewalks.

However, it does have other relevant information, including speed limits, whether a street is one-way or two-way, and whether cars, pedestrians, or both are allowed to use that street.

The sub-index labeled “pedestrian-oriented intersections” is based on the number of intersections that are accessible to pedestrians. A neighborhood with a high density of these intersections - that is, having a lot of intersections per square mile - will have a high score. This is because having many intersections reduces walking distances compared to a street network that forces pedestrians to navigate long blocks with fewer intersections.

The scoring system also takes into account the speed limit of streets, putting them into three categories:

• Auto-only intersections, where pedestrians are not permitted
• Intersections between roads where pedestrians are permitted with speeds up to 54 mph
• Pedestrian-oriented intersections between either roads where both pedestrians and cars are allowed, or paths where cars are not allowed (eg. bike trails), with speeds up to 30 mph

Obviously, auto-only intersections are an impediment to walking, while having many of the other two types will make it easier for foot traffic.

While not used to calculate the index, the density of roads (not just intersections) provides important context too. (This data is available in WalkabilityIndex.com report pages.) Dense and walkable urban neighborhoods will have a high density of roads compared to a rural area. For example, one Berkeley neighborhood with a walkability index of 20 (the highest possible) has a total road density of 33 miles of road per square mile. In comparison, a rural neighborhood might have just 1 mile of road per square mile.

Category explanation: Distance to Nearest Transit

Finally, access to public transit (ie. city buses, street cars, and subways) makes up the final component of the walkability index. This last sub-index is based simply on the distance from the population center of a neighborhood to the nearest public transit stop of any type. The closer the transit stop is to the population center, the better the score. Any stop farther than 0.75 miles doesn’t count (because it’s too far to walk for many).

Public transit is important because it makes it possible to navigate a metropolitan area without a car. Without public transit, walkers are limited to a much smaller geographic area. Even cyclists can benefit from public transit, because many city buses have bike carriers, and bikes are also allowed on many rail systems.

Of all the components that make up the walkability index, this one is perhaps the most limited. This is because it’s based only on the distance to a public transit stop, which leaves out a lot of other information that makes a public transit system useful to people, such as the frequency of service, and the number of routes and stops in a neighborhood.

That said, if there is a public transit stop that happens to be very near the population center of a neighborhood, that’s likely correlated with a transit system with a higher total number of stops and frequency of service. Transit stops don’t exist in isolation, and unless that one stop just happens to be located near the neighborhood population center, it’s more likely than not that there are more stops nearby.

There is more data available in the walkability report, including frequency of rush hour service and how many people in the neighborhood live within a 1/2 mile of a rail stop (ie. subway or commuter rail system), that can provide a deeper insight into the quality of a local public transit system.

Summary: walkability isn’t just one number

As you can see, there’s a lot involved in trying to measure the walkability of a neighborhood. While distilling it down to one number – like the Walkability Index does – has value and makes it easy to compare neighborhoods, you need to dig deeper to understand whether a place will be somewhere you can sometimes leave the car at home, or even go car-free entirely.

Fortunately, the reports on this website provide dozens of data points that can help you better understand any place where you want to live.