[3] The Brazilian Institute of Geography and Statistics (IBGE) defines the region as a "metropolis" in its Area of Influence surveys, in terms of economic and social importance.

[4] The region's area of influence covers a large part of Northeast Brazil, including the entire states of Alagoas, Paraíba, and Pernambuco, in addition to portions of Bahia, Ceará, Maranhão, Piauí, Rio Grande do Norte, and Sergipe.

Within this area of influence are the smaller cities of Natal, João Pessoa, Maceió, and Aracaju.

[7][8] The Immediate Geographic Region (formerly termed microregion) around Recife defined by the IBGE[9] encompasses additional outlying municipalities.

[citation needed] Buses transport over 3 million passengers daily[17] through 224 routes and 4,523 stops.