# A Comprehensive Survey on the Societal Aspects of Smart Cities
## 2 Smart Cities Dimensions
### Smart Mobility  
Mobility is a crucial concern for urban residents, as different services are geographically distributed. This is particularly significant for those in lower income brackets, for whom a reliable and affordable public transportation system can improve job availability, access to services, and overall quality of life. Public transport systems also help to reduce the number of cars circulating, easing traffic congestion, and reducing carbon emissions and air pollution. Therefore, improving mobility is a key aspect of smart cities. Enabling efficient movement of people and vehicles provides inhabitants with better access to city services, job opportunities, and intercity trade. This can be achieved through various strategies, including but not limited to the development of a reliable public transportation system, the provision of real-time transit information, smart traffic signals, and the use of autonomous vehicles. Specifically, services such as Uber or Lyft enable individuals to request a ride from a pool of drivers using their personal vehicles or to become drivers themselves. Self-driving cars are another technology that could significantly impact mobility in cities; however, to achieve full autonomy, they require not only adequate computing resources but also the support of a smart city's infrastructure [92]. Travel in cities is not limited to traditional motorized vehicles, which means that the cities' infrastructures should be restructured to accommodate non-motorized vehicles (e.g., footpaths, bicycles' lanes, or bicycles' sharing), as already happens in many of them, since cycling is a common transportation modality in many countries across the world, with some (e.g., the Netherlands or Denmark) relying on it as their primary mode of transportation [93]. However, cycling requires widespread networks of vehicle charging/parking stations as well as bicycle paths that allow users access to a wide range of destinations, which often requires expensive and time-consuming restructuring of a city's layout. Nevertheless, this restructuring is part of the effort of smart cities to decrease their transportation environmental footprint by focusing on electric vehicles, public transportation, and other non-polluting alternatives, and thus already being implemented and expected to continue and accelerate into the future [94; 95; 96]. Under the remit of smart mobility is included the building, upgrading, and maintenance of the transport infrastructures. Creating new types of roads that offer advantages over traditional paved roads, such as solar roads, which are composed of photovoltaic panels and would produce electrical energy all through the day, or plastic roads, which would be built not out of asphalt but of plastic [97]. In turn, several components of the mobility infrastructure can also be upgraded, such as, for example, smart signage that informs users of accidents on the road, automatic lighting that can turn off when there are no vehicles, and direct monitoring of important infrastructure (e.g., bridges, railway crossings, or pedestrian crossings) [98; 99; 100]. Moreover, maintenance can also be improved by allowing the citizens to report issues using digital applications, which enables the authorities to allocate maintenance crews to problem spots as soon as they appear and prioritize according to need [101]. However, roads and the vehicles that use them are not the only ways smart mobility applies to cities. For cities that have them, seaports and airports are major connections for national and international trade and tourism. However, managing such critical structures and the traffic they generate is not easy, requiring skilled labor and complex infrastructure. Therefore, applying smart technologies to them can bring great benefits. From, among others, creating systems to optimize airplane routes, landing and takeoff schedules, automated maintenance scheduling, and sensors to detect faults.