A/B Street (abstreet.org) is an open source traffic simulator built on OpenStreetMap and public census data. It simulates car, bicycle, foot, and public transit traffic, and runs on Mac, Windows, Linux, and directly in the web browser. A/B Street allows the user to reallocate existing road space between cars, protected cycle lanes, transit-only lanes, and street parking. Users can also modify traffic signal timing and create access-restricted neighborhoods. Individual and aggregate results from the simulation can be compared before and after the changes, creating a simple way to evaluate potential changes.

A/B Street has been designed for the general public to easily explore proposals for reducing dependency on cars. This talk will cover some specific cases in Seattle where the software has been used to propose real changes, like opening a shortcut through a gated community for cycle and foot traffic to avoid dangerous roads. We'll discuss how to start using A/B Street in your area, the challenges in finding other open data-sets required, and some options for how to publish results.