[ahstilde]

> A megalopolis (/ˌmɛɡəˈlɒpəlɪs/) or a supercity,[1] also called a megaregion,[2] is a group of metropolitan areas which are perceived as a continuous urban area through common systems of transport, economy, resources, ecology, and so on.[2] They are integrated enough that coordinating policy is valuable, although the constituent metropolises keep their individual identities.[2]

2 hours driving, in the US, is a natural distance for complementary but distinct cities to form. NYC/Philly/DC, SF/San Jose, LA/SD.

Megapolis is the correct term.