Nigeria is using a high performance network for the national post office (1,500 locations) to jumpstart community broadband connectivity. A new national backbone will be built, using the post office needs as an anchor tenant. But the high performance network will be designed to support other community broadband and service needs.
This could work well in the U.S. at the regional and state level, and in fact, states like New Mexico are already studying just that--using state library, telemedicine, and research network needs to serve as the backbone for an open network available to businesses, residents, and service providers (Disclaimer: Design Nine was hired by the State of New Mexico to do that study).
Private, single use networks are expensive and often limit economic development potential, because a dedicated K12, health, or state agency network usually can't be shared with the private sector. By building a single high performance network like the one planned for Nigeria, several anchor tenants can help offset the cost and not only lower the cost of telecom for their own organization but for the whole community as well. Some places in the U.S. are planning these networks, including the Eastern Shore of Virginia Broadband Authority.