Mixed-use is at the very core of smart growth. Rather than forming districts segregated for housing, retail, office, etc., a well-designed neighborhood will integrate all of these. Single-use land tracts alienate those not there for that specific purpose, creating closed off and isolated communities. Mixed-use neighborhoods also decrease traffic, due to their general connectedness and proximity to transit. Preventing sprawl should be incentivized, providing a benefit to communities and developers alike.