I am mapping the accessibility of job opportunities in Detroit for those who rely on public transportation. To do this, I need to create a circular buffer surrounding each bus stop with a radius extending out a mile in every direction. One mile represents the average time it takes a person to walk 20 minutes, a value chosen based on empirical research that an average person walks 4.5 feet a second (or 3 miles per hour).

In ArcGIS 3.0, I only see a "Variable Distance Buffer" tool under Vector--> Geoprocessing Tools. enter image description here (See pic below). But these fields are not intuitive to me, even after clicking the help button. Where and how do I specify 1 mile for the radius measurement to extend out from the point in all directions? P.S. I should add I do not yet know python, so looking for alternative solutions.


I think you are currently using QGIS 3.0.0 or 3.0.1.

Latest QGIS 3.0.2 does not have Variable distance buffer anymore.

What you can find in the Vector | Geoprocessing Tools menu would simply be a Buffer.

enter image description here

It is the same in the Processing Toolbox... First. Fixed distance buffer disappeared, and now Variable distance buffer. There is only Buffer tool left.

enter image description here

Now with this Buffer tool, you will easily find Distance option. In case you need to apply a variable distance, click on the Data defined override icon and select the field you want to assign to.

  • I looked at this buffer tool, as well, and I'm unclear what units the "distance" field is measured in. I want to measure 1 mile – Ashley Apr 24 '18 at 12:54
  • @Ashley The unit is the map unit, which is based on your projection. – Kazuhito Apr 24 '18 at 13:07
  • @Ashley You might want to try 5280 (ft) for 1 (mile) and see how it goes. – Kazuhito Apr 24 '18 at 13:24

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.