As driving to the shops, and ownership of two cars per family, became the norm, out of town retail parks prospered. Between the 1980s and the '00s, many enclosed shopping centres and outdoor parks were built, often on brownfield sites or in the suburbs. Similar types of shop, for example sporting goods or office supplies stores, are often grouped together. Retail parks are often served by bus, rail or tram links, with their own stop or station, and situated near major road routes. Minor roads may be built, or existing ones widened, for ease of access. Several retail parks may be grouped along one road, a short drive apart.