What can adjoining cities do when one city is doing well and the other poorly?
Grosse Pointe Park, Michigan has been in the news because of a couple "urban design interventions" they've done that sever through streets that would normally connect the city with Detroit ("Cross-border drive that symbolized city-suburb disparity blocked permanently for farmer's market," MLive).
They've installed sidewalks across through streets and a farmers market shed blocks another street, although they've just agreed to take it down and work with the City of Detroit on a mutually agreeable "gateway" ("Detroit and Grosse Pointe Park reach deal to create 'gateway' along the cities' controversial border," MLive).
Detroit is a shell of its once great success, as more than 1.2 million residents have moved out of the city over the last 60 years. The population of Wayne, Oakland, and Macomb Counties as of the 2010 Census is only about 100,000 more people than in 1960.
The difference is that it has been redistributed mostly out of Detroit and to some extent out of Wayne County. (The metropolitan area has also grown in that time, accounting for greater growth than just within the three counties.)
That matters because ultimately, neighborhood revitalization is dependent on demand for residential building stock.
The Detroit News editorializes ("Grosse Pointe Park stands up to blight: Controversy over blocked road overshadows community's pro-active effort to keep its downtown healthy") in favor of Grosse Pointe Park's acts, justifying them as a form of community protection and maintenance of a successful commercial district.
Instead the newspaper ought to be positing ways that the communities might be able to better work together to spread success back into Detroit, rather than celebrating Grosse Pointe Park's hunkering down and building walls between the communities.
Revitalization is sparked most easily by building off current success. So what I would recommend is the creation of a Jefferson Avenue-East Side Detroit Revitalization Plan focused on leveraging the success of the Grosse Pointes--the five cities have a very high per capita income--the Ford Family tends to live in this area, amongst others.
But the big problem is lack of substantial demand for housing in the Detroit metro area, let alone in a declining area of Detroit, and a willingness to pay the very high property taxes that Detroit charges--taxes are high to raise the funds needed to cover the infrastructure that remains for the whole city, even though much is now unpopulated.
(One solution is a long term abatement on property taxes on new housing. Philadelphia and Baltimore have done this. But such an abatement, in a city that is broke, could be problematic.)
Concentrated renewal is necessary. The other problem is that outside of Detroit's Downtown, the areas of relative success are in the bordering communities on the east (Wayne County) and west (The Grosse Pointes), and theoretically in the north (Oakland County), not in Detroit. Although judging by Google Earth, much of Detroit's west side seems intact, including neighborhoods where I used to live, even if housing prices are low.
To focus Detroit's redevelopment in the outskirts of the city militates against concentrated renewal. Since Downtown is successful as it becomes a mixed use district, the city needs to focus growth there and as demand increases, work to recover adjoining areas, expanding outward.
In as dire straits as Detroit is, very difficult choices have to be made on where to invest public resources in order to maximize the likelihood of success.
Perhaps some of Detroit's land needs to be able to be "deaccessioned" and revert to township status, and the opportunity for renewal in those areas could shift spatially from the core/Detroit, to the energies present on the outskirts, such as the Grosse Pointes on the east side.