Low-traffic neighborhoods

Launch the tool in your web browser

This tool lets anybody study existing and proposed low-traffic neighborhoods (LTNs). Experiment with modal filter placement, and examine the impacts on drivers trying to cut through residential areas.

The software runs faster if you install it. No mobile/tablet support. Unzip, then run ltn.exe or ltn.

Contact dabreegster@gmail.com with any feedback or file an issue on Github.


(As of September 2022, some of these notes are out-of-date or feature old screenshots.)

You can place new modal filters (planters or bollards) along streets or diagonally in intersections. Filters will calm traffic along that one street, but may just find detour around it. Only when you split the neighborhood into smaller "cells" does the amount of through-traffic in the area get reduced.

The tool also detects existing modal filters today, based on on OpenStreetMap data.


You can explore individual paths through a neighborhood that drivers may take, and a heatmap predicting which streets are likely to experience more or less traffic.

Plan a route

If you want to understand how filters will affect your driving commute, you can explore a route before and after a proposal. Main roads are often the fastest route anyway, but you can adjust the level of traffic jams to see when it may be advantageous to take a shortcut through a neighborhood.

Neighborhood boundaries

The tool starts by classifying everything inside "major roads" as a neighborhood, where ideally there shouldn't be much through-traffic. But you can adjust these boundaries however you like, merging two neighborhoods or placing a local high street in the "interior" of your LTN, even if it serves lots of traffic today.


Once you create some filters or adjust neighborhood boundaries, you can save your proposed changes. You can open and then compare multiple proposals. You may also export all neighborhood boundaries and filters to the GeoJSON format, and then work further in QGIS or your favorite tool.

NOTE: Proposals are only saved on your computer (in the data/player folder for the downloaded version, or in your browser's local storage). There's no support yet for sharing proposals online.

NOTE: Proposals saved with one version of the software might not work in future versions. I'll aim to guarantee backwards compatibility by mid-March. In the meantime, if you ever have trouble loading your previously saved work, please contact me and I'll help.


The tool traces around areas surrounded by major roads, using this to determine interior roads that should have minimal through-traffic. You can adjust the default boundaries. Unfortunately, this feature is broken in some cities, particularly where bridges and tunnels overlap other roads. Track this issue for updates on progress.

There are some advanced / experimental features that don't work yet:

  • Automatically placing filters to optimize some definition of a "good" neighborhood
  • Predicting the overall impact of a proposal on vehicle traffic in the area. This requires a high-quality travel demand model to know where people currently try to drive, and coming by these isn't easy.

Other planned features

  • Change between one-way and two-ways streets, which is a less common way to effectively introduce filters
  • Overlay bus routes, and introduce bus gates (filters that buses can pass through)
  • Visualizing and editing other traffic calming (speed humps, chicanes, curb extensions)
  • Predict how much traffic will "dissipate" in response to LTNs, as people switch their travel behavior long-term.


Main team:

Alumni from A/B Street (the LTN tool is built upon past work):

  • Michael Kirk
  • Yuwen Li

None of this work would be possible without OpenStreetMap contributors.

Inspiration / early testers giving great feedback:

This work was expanded from an initial prototype while Dustin worked at the Alan Turing Institute, where he's funded by the UKRI grant for the ASG program.

Current users

Planners from these cities are currently using a prototype of the software:

  • Nottingham
  • Lyon campaigning group

If you're using the tool and are willing to be listed here, please let me know, so I can make the case for funding further development.

Concept art

Our hope is that this tool makes it easier for communities to come together and collaboratively design neighborhoods that work well for everyone. Special thanks to Scriberia for illustrating this idea:

This image was created by Scriberia for The Turing Way community and is used under a CC-BY 4.0 licence for reuse. Zenodo. DOI 10.5281/zenodo.3332807