Introduction

There are many definitions of urban sprawl. In many studies, this term is used to cover not only the concept per se but also its causes and consequences. An interesting overview of definitions is presented in Report on Urban Sprawl in Europe (EEA, 2016) and the conclusion is that all definitions have three dimensions in common:

• • the expansion of urban areas;

• • the scattering of settlement areas;

• • low-density development.

Many authors treat urban sprawl as unplanned (Oueslati et al, 2015) or uncontrolled (Resnik, 2010) growth of cities. In Poland, Lityński (2019) defines urban sprawl as a spontaneous suburbanization. If it were planned and controlled, it would be just suburbanization. Sometimes authors propose a definition just for the purpose of a paper: ‘Here, urban sprawl is defined as a spatial growth of cities that is excessive relative to what is socially desirable’ (Ida and Ono, 2013: 2).

According to van den Berg et al's (1982) demographic life cycle of a city, Poland has moved from phase 3 (relative decentralization – the pace of growth of the number of inhabitants in a city is lower than in suburbia) to phase 4 (absolute decentralization – a decrease of the number of inhabitants in a city and an increase in suburbia) (Śleszyński, 2018).

The Report on Urban Sprawl in Europe (2016) offers a review of the main environmental, economic and social consequences of sprawl with examples of literature too. Most of the economic consequences are strictly related to environmental degradation. Bigger demand for transportation, along with costs both explicit (cars, fuels, roads and so on) and implicit (time) also has a significant environmental footprint (smog, noise, congestion). Some of these costs are borne by beneficiaries, some by local government and some constitute an externality.

There are also some positive consequences of urban sprawl; namely, families can live in bigger houses with green surroundings and more space, which translates into more privacy. However, the literature stresses serious negative environmental, economic and social consequences of urban sprawl (Burchell et al, 2002; Wilson and Chakraborty, 2013; Kowalewski et al, 2014; EEA, 2016; OECD, 2018; Śleszyński et al, 2020). The problem is that the benefits are usually private (for residents and, to some extent, municipalities), whereas the costs are public due to externalities.