Creating travel time or distance boundaries helps you understand how far you can walk, bike, or drive within a certain time from a specific point. This is useful for analyzing service areas, like the area around a fire station or the walking distance to a park.

Follow these steps to create a travel time boundary.

Open the navigation menu and click Draw a boundary.

Select the Travel Time option.

Pick a starting location on the map:

Once you've selected a starting point, choose:

When your boundary looks correct:

Your new boundary will be saved in the Layer Library.

Travel times are created using a tool called Isochrones. Isochrones reflect the total area you can reach with a particular mode of transport and within a given time.

mySidewalk utilizes the isochrones plugin to pass your starting point and selections on time and mode to the Mapbox Matrix API to sample travel times in a grid pattern around the desired starting point. It then passes the results to a CONREC algorithm to interpolate geometric shapes out of these points (reference).

Basically, it's the same methodology that any GPS would use to calculate the distance from point A to point B. It makes that calculation a bunch of times (guess and check!) to identify the point that can be reached within the time frame you selected. Then it does that all the way around your selected point until it makes a shape around your chosen location!

Note: The travel times are calculated based on average travel time for that area and currently do not take into account topography.

Travel distances are created using a tool called Isodistances. Isodistances account for roads and sidewalks in calculating travel distance, so they offer a more realistic travel radius from your origin. They are useful when you want to know what’s nearby, and precise distance is very important to you.

mySidewalk utilizes the isodistances plugin to pass your starting point and selections on miles and mode to the Mapbox Matrix API to sample travel distances in a grid pattern around the desired starting point and deliver a boundary back to you.

Now that you've created and saved your travel time boundary, you can use it like any other geographic shape within mySidewalk. Here are a few ways to apply it:

Travel time or distance boundaries can also be used to apportion data in mySidewalk. This is helpful for comparing multiple geographies or extracting data points specific to the area within the boundary.

You can use your new custom geography as the default geography in a report template. For example, drop a pin on a proposed park location and get a walking boundary around it to understand the area that the proposed location would serve. Save the boundary and use it in a population and demographics report template. This will give you an overview of the type of population that proposed park location will serve.

Maps are a great way to visualize data inside a boundary. You can create a bivariate map using crash data, vehicle data, and a custom cycling boundary around a bus stop to visualize a correlation that might be there. First, you would create the boundary by dropping a pin in the travel times tool and creating a cycling boundary around the bus stop. Then you can use that boundary in a map (pick a sub-geography like census tracts) and select “Style by Data” to choose crash data. Once you have chosen a first dataset, you can toggle on “Bivariate Mode” and select vehicle ownership information for your second dataset. This map can be published or copied to a report to share your findings with others.