Blueprints are one of the tools created in the game to facilitate the management and expansion of the city. They can be named and saved to a separate file, allowing you to reuse them across all your cities. Blueprints capture roads and expressways, as well as zoned lots and amenities like schools and parks[verify], allowing you to make repeatable neighborhood layouts. They can be rotated, flipped and adjusted to be inserted in the best way possible in the road layout of the city.
Blueprints are saved globally, meaning any blueprints a player has saved are available in all files, and between regular play and Test Mode. Either a single blueprint or the entire blueprint library can be copied to your clipboard as a plain text string. You can also paste Blueprint strings into the game. This enables player to share blueprints with others in text form, similar to the factory building game Factorio.
Test Mode[]
Test Mode is a gameplay mode accessible from the menu at any time, which loads a smaller map with all Roads and Expressways unlocked, for the purpose of planning, testing, and saving blueprints for Interchanges and Blocks. The loaded map is perfectly flat, lacking trees, water, or changes in elevation (save those created by creating ramps out of Roads). In Test Mode, cul-de-sacs will not be drawn on dead-end nodes, and cars will randomly spawn at dead ends and navigate the road system towards a random destination, to simulate traffic flow.
Test Mode uses the same save system as cities, so be careful not to save over your current game when exiting Test Mode back to your city.
References[]
https://www.newcities.io/2019/10/25/planning-for-success.html