Evaluation of the rationality of transportation network distribution and its impact on social and economic development have great significance for building an efficient and comprehensive transportation system, which is also an important research topic in economic geography and regional economics. Because evaluation indicators to express the characteristics of transportation network distribution at the macro scale are lacking, this paper selects three indicators—highway network density, transportation network proximity, and location dominance related to the central city—to form the basis of an integrated transportation network distribution index for characterizing China’s transportation network distribution using geographical information system technology in 2015. The research shows that transportation network distribution is low in most Chinese counties, and that there are obvious differences in distribution between counties in the east and west in addition to identifying multiple dense areas of transport layout distribution. Transportation network distribution is intrinsically coupled with social economic development: the more complete are transportation network facilities, the greater the population density, and the higher the level of economic development. The results highlight the need to focus on strengthening population concentration and economic development in areas with good transportation network distribution. The study can guide the optimization of transportation network structures and provide a macro decision-making reference for planning and evaluation of major transportation projects in China.