I used to work on the router used in VZ Navigator and related products (I wrote the part that used real-time traffic data to route around slowdowns, plus severa

I used to work on the router used in VZ Navigator and related products (I wrote the part that used real-time traffic data to route around slowdowns, plus several other bits). After leaving, I started writing my own router on top of OSM data (fall 2008). The difference in quality of Navteq and other vendor data vs. OSM was substantial, and I abandoned the project simply because shit data is impossible to optimize for. It looked great on a map, but disconnected road segments, incorrect road categorization, incorrect directions of one-way streets, missing intersections, ... I wasn't at all surprised at Apple falling on its face in 2012 with its OSM-backed maps product - it was a virtual guarantee from my experience. Likely a missed opportunity for a big exit for me, but life's too short to work against poor-quality crowd-sourced data as a one-man startup in Venice.