Towns & Growth
Let’s have a look at towns, the places where the inhabitants of OpenTTD live. Each town has a population, based on the number of buildings and how many inhabitants each building contains, which can grow or shrink depending on certain conditions. What are those conditions? Well, first, let’s see what towns are made up of.
Most buildings in the towns provide a source of passengers and mail which can be transported to other towns or within the same town. However, during a recession there will only be half of the usual amount of both passengers and mail. In some cases, buildings may also accept other cargo such as goods, food, or water, depending on the environment. For a station to accept any one of these three, the buildings in the station’s coverage area must be able to accept a total of at least 8/8 of the cargo. The coverage area highlight option, shown in use to the right, will help to find out what the cargo acceptance of individual buildings would be.
There are two town industries which are environment dependent. Firstly, Banks can be found in towns with populations of over 1,200 in Temperate maps, and in towns with any population in Sub-Arctic maps. Secondly, Water Towers may be found in desert towns in Sub-Tropical maps.
The population of towns can increase, providing more passengers and mail to transport. The towns will grow every so often, either very slowly on their own or a bit faster with help from transport companies. The effects of town growth will be the townspeople constructing new buildings on empty tiles next to roads, or demolishing and replacing existing buildings with larger buildings, sometimes causing temporarily dips in town population while the new buildings are being constructed. Furthermore, sometimes new buildings will increase the number of cargo accepted in a town, such as goods, food, or water. Regardless of whether services are provided, towns will grow very slowly over time, however, town growth may be influenced in several ways.
General conditions for town growth
Finally, we’re getting to the conditions for speeding up town growth. So, town growth can be accelerated by loading and unloading at least one item of cargo at up to five stations within town influence within a two month period. It doesn’t matter which type of cargo is loaded or unloaded and extra amounts of cargo beyond the first item don’t have any extra effect. The towns will then expand physically by extending roads onto empty areas of the map and constructing new buildings next to the new roads. This means that pre-built road networks can actually speed up town growth because the town can then just build houses all the time instead of houses and roads. However, roads can’t be built over diagonal train tracks or tracks with signals on them, so be careful to not block a town in. The two images below, from the OpenTTD Wiki , show a town which is blocked in on the left and a town which may grow freely on the right as an example.
There are also cities which are a special form of town that grow twice as fast as a regular town. A big city needs plenty of space, and without obstacles, a population of one million requires around a 150-200 tile diameter.
Climate-related conditions for town growth
- Temperate, Toyland: There are no special conditions for a Temperate or Toyland town to grow. Simply load or unload cargo as mentioned earlier to speed up growth.
- Sub-Arctic: If the centre square, as determined by the square upon which the sign with the town name sits, is not above the snow line, food is not required for growth, although food will still be accepted. If the centre square of the town is above the snow line, at least one tonne of food per month must be delivered for the town to grow rapidly. Towns will still grow very slowly on their own, so in the case of small towns that are not large enough to accept food, it is simply a case of waiting for them to grow to a size at which they can accept food. However, the actual amount of food that is delivered will have no effect on the rate of town growth.
- Sub-Tropical: If the centre square is not in the desert, food and water are not required for growth, although Water Towers may exist in the town and both food and water will still be accepted. If the centre square of the town is in the desert, at least one tonne of food and 1,000 litres of water per month must be delivered for the town to grow rapidly. The town itself will still grow slowly without food or water and the quantities of each will not have any effect on the rate of growth, just like in the Sub-Arctic environment. The supply of water, must be delivered to a Water Tower industry which may be generated automatically in towns, or one may be funded.
Tips for Town Growth
A bus service is the simplest way to increase the population of a town since the requirements for accelerated growth are “at least one item of cargo”, not the quantity of cargo being transferred. Therefore, a bus with one passenger from the other side of that same town would have the same effect on growth as a large train full of passengers from the other end of the map. Although, if this is on a Sub-Arctic or a Sub-Tropical map, the other conditions for growth still apply.
Furthermore, remember what a feeder station is? Well, a town with a feeder station where cargo is picked up but not set down will also grow.
Also, using Fund New Buildings from the Local Authority window may result in rapid population growth for a short time, or increase the areas where the town accepts goods, food, or water, allowing more cargo types to service the town and increasing the growth rate. However, remember that delivering goods specifically does not have any extra effect on town growth in any environment other then increasing the types of cargo which are being supplied.
Town buildings will extend outwards based on the transit distance, not vector distance, along the road from the town centre, i.e. where the sign showing the town name is displayed. If you’re not sure what this means, check out the section on transit distance in Delivery Payment Rates again. Roads which are close, but do not connect to the town centre, will have no buildings constructed alongside them because there is no way for the population to travel to such locations.