This chapter presents how spatial network adjustment on transportation infrastructure can provide sufficient accessibility to the market and to the society. In particular, the argument focuses on a situation when a change of social dimension, such as long-run population decline, is observed. Since such areas face insufficient economies of scale to engage economic activity, it is also necessary to adjust the organisation of market areas. This methodological framework leads on to regional policy for establishing more effective spatial planning and design under the condition where local governments face severe budget constraint to provide public services.