The way your city is laid out in City Builder is crucial to success. Roads must be far enough apart, but not too far, so growth is not inhibited. Positioning of stations also needs to be taken into account.
Also a really detailed Town growth OpenTTDcoop guide
- Destroy existing roads if necessary
- Alternating stations
City layout is essential for creating a town beyond 10 thousand inhabitants. Constructing a 7x7 station 10 tiles away from town center is an easy way, but, inevitably, town's growth zone will be blocked by it. Spiderweb layout has four growth directions. Each one of these directions has to be free from any obstacles, like industries, towns or stations. That is why a player should strive to keep central axis clear and utilize maximum acceptance range of 25 tiles from town's center.
Most of passenger & mail cargo comes from inside the city. Hence, the alternating spread between Moriarte City South & Halt and other stations alike. Effective catchment area of two mentioned stations is approximately 80 tiles, which allows full transportation from 80 houses with just 10-15 buses. Entire pax system can transport vast number of passengers (above 10k passengers every month, beyond 40k city population) using 40-60 buses. When a city grows beyond 30 thousand people it is wise to expand passenger service beyond the central 'growth zone' by building new stations for pax and mail. City Sidings station is used for pax trains coming from other cities. Usually connecting 6 nearby cities is minimum for a megapolis.
Valuables (City Woods & Sidings)
City Sidings station also is used for storing valuables if every passenger train has 2 valuables cars attached. After town population reaches 2,500 citizens, a single truck should be bought to load at Sidings and unload at Woods. Woods station shall therefore be expanded, so the bank is in the catchment area.
Power Stations (City Annexe, Station #17, Station #18),
Advanced players like to claim a town without a power station and build it at the spot, where it would be most effective. (i.e. not blocking potential city size). City Annexe station can sustain 5-6k cargo each month. Therefore, if someone aims to build a city beyond 50k population, stations #17 & #18 are needed. Fully supplied, all three stations can provide a city with up to 10k of coal every month.
Factories (Upper & Lower City and City North & Branch)
Construction of two factories is a good way of building up stocks of goods on stations. In a late stage of the game player can boost town's goods storage by adding more goods trucks to stations: Upper & Lower Moriarte City and City North & Branch. Three full lanes of trucks at each factory allows the delivery of 10k goods (and beyond) every month. Furthermore, using two factories instead of one allows easier connection of livestock and grain scattered around.
Building too many roads at any stage in the game will result in increased construction of small houses. Building small number of roads will cause a game to construct/rebuild more highly populated tall office buildings. One way roads keep vehicles 'locked' inside station lanes, which boosts volumes of cargo transported on a monthly basis.