Mining map data to predict turn restrictions

Abstract

Disclosed herein is a system for mining map data to automatically identify and/or predict turn restrictions. The systems uses street-level imagery to recognize and locate posted signs (e.g., physical signs, electronic signs) that signal, or are in some way related to, a turn restriction at an intersection. Then, the techniques use a cascade of machine learning models to accurately predict whether the recognized and located signs impose the turn restriction at the intersection. Consequently, the human effort required to identify turn restrictions is greatly decreased, if not completely eliminated. Furthermore, electronic maps can more efficiently be expanded and/or updated which improves the experience for vehicle drivers that reply upon the electronic maps for directions from original locations to destination locations.