Carrying capacity is in relation to the maximum an ecosystem can hold while still maintaining function. A city’s roads have a maximum amount of cars that can drive on them without creating standstill traffic. This means that there is an optimal number of cars for city roads, and until that number is surpassed, the roads will be flowing and functioning. In this way, the carrying capacity of an ecosystem has an optimal number of organisms given the environment’s resources, and surpassing that will affect proper function.