Historical determinants of street connectivity in Japanese cities: Relationship between Japanese castle town formation, war damage, and space syntax integration value

Are street networks today dependent on history? This question is significant when considering the determinants of street connectivity and the potential for intervention toward walkable street networks. This study investigates the associations of two historical events—castle town origination and war damage during World War II (WWII)—with the street connectivity of 803 Japanese cities. We used the space syntax theory to measure street connectivity and conducted multiple linear regression analyses to determine the aforementioned associations. The results showed that street connectivity today tends to be low in cities that originated from castle towns and high in cities that suffered heavy damage during WWII. This may be due to complicated street networks that were constructed intentionally in castle towns to defend their territory from invasion. The remaining irregular layouts may have directly and indirectly influenced today's street networks. Furthermore, in the cities that suffered heavy war damage, the “postwar reconstruction city plan” was enforced to reconstruct affected areas, which may have improved street connectivity. These findings highlight the significance of historical events in the consideration of street connectivity determinants and the development of interventions to enhance them.