As a construction simulation game, Cities: Skylines gameplay is usually time-spending and requires plenty of commands from players. Get those simply done with mouse clicks will be a catastrophe. However, the default setting provides few shortcuts which are hard to deal with complicated controls, and few players comes up with an easy-using shortcut layout.
Here is my personal recommended shortcut layout for Windows CSL players that covers almost all main controls and even some popular mods without any conflicts. Some of them suggest their functions so it could be easy to memorize. For your reference.