Bike Routing
Tweaking bike routing

Routing is a hard problem. Routing for drivers is pretty good at this point, mostly because we have been very good at designing for cars and creating predicable infrastructure. Routing for bikes is a whole other story, data quality is poor and the physical infrastructure is, at least in North America, not strongly predictive of cycling comfort/safety. And cycling comfort/safety is the top priority for the vast majority of (potential) cyclists.