游戏官网开发者论坛文章：Cities: Skylines - Dev Diary 1: Roads《城市：天际线》开发日志1：道路
When we started designing the road building tool we wanted it to be as versatile as possible, aiming to recreate the possibilities of Cities in Motion 2's road building tool. We also wanted to give the tool more accuracy so that creating square blocks for city centers would be easy.
When building the roads, the tool also creates the zoning grid on both sides of the road which indicates the area where zoneable buildings are built when the player uses the zoning tool. The grid is visible while building the roads which gives the player the ability to create optimal city blocks if they so choose.
The road upgrade tool can be used to upgrade or downgrade roads. It can be used to upgrade a small road into a medium or large road or a small road without decorative elements into a road that has them.
The game features several categories of roads from small roads and oneway roads to large roads and highways. Small roads are the basic road type for suburbs with slower speed limit and noise pollution. Medium roads and large roads can service larger amount of traffic but in turn generate more noise pollution. Oneway roads are a good alternative especially to basic roads and they also work as the road type for roundabouts. Highways are useful for connecting the different parts of a city together as well as the outside world when speed is essential and the effects of noise pollution are not an issue. There are decoration variations for most of the road types from small roads with decorative grass and trees to highways with sound barriers that block some of the noise pollution from spreading. In general the decoration variations cost more to build and maintain but in turn they create less noise pollution and increase land value.