Infrastructure

For the cost of transporting goods over sea, see convoys.

Infrastructure and market access on the state overview screen.

Infrastructure simulates the cost of transporting goods over land and creating the necessary foundation to support wide-scale industrialization.

To industrialize a state, it isn't simply enough to build heavy industries and have the pops available to work in them. The player also needs to ensure that there is sufficient infrastructure to support those industries.

Infrastructure ties into several mechanics, such as market access, military logistics, and migration, among others.

Infrastructure sources

Infrastructure is provided and modified by numerous sources. All states have a base of +3 infrastructure.

Population

All states gain some infrastructure from the size of the state's population once certain Society technologies have been researched. The relevant technologies are in the branch of the Society technology tree beginning with  Urbanization. The amount of infrastructure gained in this way can be viewed in the tooltip for the Infrastructure value in the Information tab of the State panel, where it is called “Infrastructure from Pops”. It is based on the number of individuals (including Dependents) living in the state and capped by the same technologies, using the formula:

${\textstyle {\text{state infrastructure from Pops}}=\min({\dfrac {{\text{population size}}\cdot {\text{Infrastructure from Pops (modifier)}}}{\text{100,000}}},{\text{Max Infrastructure from Pops}})}$

Almost all countries (including many decentralized ones) start the game with at least one of the relevant technologies researched, and so have some infrastructure from population. Note that the precise value shown in the state's UI tooltip is rounded down to one decimal place.

The law  Serfdom reduces the Max Infrastructure from Pops by −20%, limiting the benefit of dense population significantly.

State modifiers

See also: State traits

Coastal states receive a flat +2 infrastructure, as well as the ability to build ports.

Many states have a trait which adds or reduces infrastructure. States with important waterways, such as the Mississippi or Rhine rivers, receive a flat bonus to infrastructure; while states with difficult terrain, such as mountain ranges, deserts, or notable forests, receive a percentage penalty to infrastructure.

The  Road Maintenance decree provides an additional +1 Infrastructure from Pops and +20 Max Infrastructure from Pops, which is useful to offset temporary penalties from turmoil or devastation, or supplement infrastructure until more railways can be built. Unincorporated states receive a −25% penalty to infrastructure. Devastation reduces infrastructure in equal percentage to the amount of devastation present. Particularly in unincorporated states or states with traits that reduce infrastructure, this can result in 100% penalty to infrastructure, effectively isolating the state from the wider market.

A country's  market capital state gains +25% infrastructure.

Ports

 Ports provide a small amount of infrastructure with most production methods. This can be useful in the early game before railways to gain some extra infrastructure in coastal states, but the amount provided is low compared to railways, at most +10 per level, and this is not the primary purpose of ports, so it is not as efficient, especially once railways are available.

Railways

 Railways are the primary and most efficient method of increasing a state's infrastructure. In addition to infrastructure, railways also produce transportation, which is used for some production methods and also as a pop need. Initially, railways produce +20 infrastructure per level (with the  Cargo Prioritization production method), and with more advanced train production methods, this can be increased up to +40 per level.

Other

Certain events provide bonuses or penalties to infrastructure and the Rural Folk's loyal trait  Farmer's Markets provides +10% infrastructure in all owned states.

Infrastructure usage

The infrastructure usage of a state is determined by the types and levels of buildings in the state. Generally, the more urban and specialized the building, the more infrastructure it uses per level. For example, chemical plants use three infrastructure per level, while  rye farms use only one per level.

Most buildings within the same general type have a typical infrastructure usage:

• Agricultural buildings, plantations, and resource buildings other than mines use 1 per level.
• Government Administration, Universities, and monuments use 1 per level.
• Mines use 2 per level.
• Factories use 2 (light industry) or 3 (heavy industry) per level.
• Military buildings and construction sectors use 0.2 per level.

Not all buildings use infrastructure, and average usage tends to around 1 per level in the early game and to around 2 per level as more heavy industry is built.

Market access

Market access starts as simple calculation of infrastructure over infrastructure usage. If the state has higher infrastructure than usage, market access is 100%, but if usage exceeds available infrastructure, market access is reduced by a proportional amount. For example, if a state has an infrastructure of 45 with a usage of 90, its market access is only 50%. States which are overseas from the  market capital also require shipping lanes and convoys; therefore, market access in such states can be reduced despite a sufficient supply of infrastructure. Similarly,  isolated states, whatever the reason, have 0 market access.

Low market access means that the state is unable to fully integrate its local market into the national market, which can lead to adverse price conditions from local over- or under-supply of goods. This imbalance goes in both directions. For example, if there is an iron mining state with a full market access, then the price of iron is the same in all states (with full market access). If the iron mining state's market access is reduced, the market price of iron increases due to undersupply while the local price of iron in the mining state decreases due to oversupply. At the same time, input goods often have the reverse effect. So in this example, tools would become more expensive in the state and less expensive in the wider market. As such, particularly low levels of market access can severely impact the local economy of a state, leading to an increase of radicalism and turmoil.

Good market access is essential for the production of complex goods. It is required both for sourcing specific input goods from another state in the national market (or via an import from a foreign nation) as well as for reaching a large enough population who can afford to buy them.