Observed arrival · 2026-09-16
Lefty: Routes Around the Hard Turns
A navigation tool that compares the fastest route with one designed to avoid unprotected left turns and undivided high-speed roads.
Field notes
The routing study compares 16 Toronto trips on the same OpenStreetMap data, reporting 38% fewer unsignalized left turns for an average 2.8% increase in driving time. Its map is partly maintained through a constrained community prompt: drivers are asked about an advance arrow only after stopping, and a single response cannot alter routing. Three independent answers are required, while disputed intersections remain cautious. The homepage also distinguishes municipal signal data from driver-supplied information.
Observed signals
Read the marks
Editorial observations of this landing page, not a rating.
One card from the complete issue