gravitystorm/openstreetmap-carto — pull request #571 by math1985 (2014-05-26 00:56:00+00:00)
Title: Rationalize road sizes

These changes make sure that more important roads are not rendered
smaller than less important roads.

- Render motorways from z12 on wider.
- Render trunk, primary, secondary, and tertiary on z13 and z14 narrower.
- Render casing on tertiary link wider.

This solves #256.