The primary use-case is conditionally filtering ways such as:

https://www.openstreetmap.org/edit#map=18/38.94198/-77.28127

which we are guiding the user onto in the route from DC to IAD:

http://map.project-osrm.org/?z=12&center=38.934443%2C-77.167969&loc=38.902656%2C-77.029095&loc=38.952210%2C-77.453424&hl=en&alt=0

This changeset makes `toll=yes` configurable in the profiles, disabling
them by default. Neither do we support time-based fees nor vehicle
category fees at the moment.

References:
- http://wiki.openstreetmap.org/wiki/Key:toll