The UN says half of humanity - 3.5 billion people - now live in cities, creating pressure on city energy consumption, pollution and congestion at various levels. Although cities occupy only 3 percent of available land, they account for up to 95% of carbon emissions in both the transportation and energy sectors. By 2050, more than 6 billion people, about 70 percent of the world's population, are projected to live in urban areas. The total urban space (spatial matrix of the city) and the space used for transport (transport infrastructure) are related to the dynamics and mobility of the city. The degree of mobility is determined by the number of trips of each resident to the urban space over time. Until the late 1980s, transport policy (especially mobility and environmental issues) was marginalized at EU level. Since then, steps have been taken towards a more ambitious transport policy. The unwillingness of EU member states to implement and enforce the rules remains the biggest obstacle to a better step forward in this area. In 1983, the European Parliament (EP) filed a lawsuit against the then Council of the European Communities (now the EU Council) for its inactivity in transport and mobility policy. The European Court of Justice has therefore called on the Council to start developing a common transport policy. The performance of public transport in the Republic of Croatia is regulated by the Road Transport Act. For the purposes of this law, public transport refers to the road transport of passengers or goods for commercial purposes that is provided to all users of transport services under the same conditions, and its purpose is to make a profit from the carrier.