This study investigates the impact of policy on interaction between land use and road network changes over time within cities. Policy, in this study, has been defined as the combination of the regional level government programs and political history which affects the pattern of urbanization in a region. The study focuses on urbanization in a politically volatile region that juxtaposes two completely different interaction regimes in a single city and explores the dynamics of the road network as determined by land use change. Land use change studies usually compare the landscape across different time periods and investigate the transitions and proportions of change among land use classes. Yet intensification and enhancement of the underlying road network directly influences the land use in terms of type and location.

In particular, the aim of the study is to demonstrate how land use maps can be integrated in time and space, and across an international boundary (Italy/Slovenia) to better integrate policy differences into urban systems models in general and cellular automata models. While urban dynamics have been extensively researched and simulated, the development of the road network is usually exogenous to the modeling or is ignored entirely. The primary analysis is been conducted using maps and imagery of the adjacent cities of Gorizia, Italy and Nova Gorica, Slovenia, twin towns historically divided by a political border, a line that has changed in its degree of separation from extreme during the Cold War, to minimal today. To link the findings with modeling, the SLEUTH model has been adapted to simulate the policy impacts on urbanization, allowing experimentation with incorporating policy into cellular automata models.

Further, multiple network analysis indices and measures of spatial association are used to understand the relationship between change in land use and road networks. The study was able to successfully demonstrate impact of policy on urbanization and the results show that policy influences the land use change and road networks individually but it doesn't impact their relationship. The study improves our ability to estimate the local, regional and global impacts of future (and past) land use changes on the natural and built environments. If global change is to be managed for humankind's benefit, then control and knowledge of land use change will be paramount. Simulation of policy impacts via computer modeling and visualization, and using the forecasts within decision and planning support systems, are precious for creating a sustainable future.