According to The United Nations (UN), in 2050, more than 68 per cent of the population will live in urban areas; compared to nowadays, this number will increase by 13 per cent. The rapid urbanization process causes a number of challenges: it negatively affects citizens' lifestyles, increases the number of motor vehicles in the streets, fosters climate change (such as rising temperature, weather abnormalities and the threat of food crisis), and pollution which causes the greenhouse effect.