CitizenUnit limit

What are CitzenUnits?

CitizenUnits (not to be confused with Citizens) are the game's internal data structure for 'assigning' citizens to buildings, vehicles, etc. This includes not just the residents of your city, but also visitors such as tourists, and 'temporary' cims such as emergency services workers.

A CitizenUnit is required for each household, and for every five available jobs at a workplace, for every five available customer slots at a commercial building, and for every five visitor places for an entertainment (e.g. park/unique building/park area/stadium/etc.), for every five student places at a school/college/university/library/etc., for every five patients at a clinic/hospital/gym/etc.), for every five spaces in a public transport vehicle, etc.....

You easily see from that that the number of CitizenUnits in the game can easily outpace your actual population, sometimes by many multiples.

Note that these CitizenUnits are assigned whether or not those places are occupied; e.g. even if there's no-one actually visiting that park or attending that school or travelling on that bus, the CitizenUnits still have to be created and ready to receive citizens.

Is there a limit on CitizenUnits?

The game has a hardcoded limit of 524,287 CitzenUnits; once this limit is reached, then it just can't allocate any more. It's just a fundamental game limit, like the node limit or segment limit or building limit or path limit or zone block limit or vehicle limit or CitizenInstance limit etc.

What happens when you reach the CitizenUnit limit?

Unfortunately, unlike some of the other limits, the game doesn't notify you when you've reached the CitizenUnit limit; it just carries on, quietly failing in the background. Usually the first symptom that players notice is residential buildings with 0/0 households. When they notice this, closer examination would also probably reveal that there are other (less obvious) symptoms as well.

Specific symptoms of running out of CitizenUnits include (but are not limited to):

• Residential buildings showing 0/0 households
• Workplaces with fewer jobs available than they should have
• Commercial and/or entertainment buildings with no visitors
• Public transport vehicles that can't carry passengers
• Educational buildings that can't take students

What can be done about the limit?

Officially, there's no fix for this; you've just reached the natural limits of the game.

However, a mod has been developed to increase the number of CitizenUnits for your save - More CitizenUnits.