plexity implies that the components of a system are not separable. This lack of separability is due to relevant interactions between components: The future state of components is co-determined by interactions, which cannot be enumerated, ordered, or predicted. Thus, prediction from initial and boundary conditions is limited. Cities can usefully be described as complex systems [107, 15, 16], since their components interact and co-determine their future. Thus, urban planning is limited [135] by the very nature of their complexity. This does not imply that general properties of cities cannot be estimated, but that precise prediction is hopeless. To complement this lack of prediction, living technology can serve cities by providing a greater degree of adaptability and robustness. In the next section, an overview of living technology and its properties is given. Section 3 provides an extensive (although non-exhaustive) description of urban problems and solutions offered by living technology. In particular, problems in mobility, logistics, telecommunica- tions, governance, safety, sustainability, and society and culture are discussed. Section 4 offers guidelines to develop urban living technology, using public transportation systems as a case study. The paper concludes with a discussion on the usefulness of describing cities as living systems. 2 Living Technology The term “living technology” has been used to describe technology that is based on the core features of living systems [20]. Living technology is adaptive, learning, evolving, robust, autonomous, self-repairing, and self-reproducing. Adaptation [80, 81] can be described as a useful change in a system in response to changes in its environment [52, p.19]. Living systems are constantly adapting because their environ- ment is dynamic. Adaptive technology is necessary where problems are dynamic. Certainly, there are different degrees of adaptation: a thermostat adapts only to changes of tempera- ture, while an autonomous car has to adapt to changes in roads, traffic states, other vehicles, 3