The road and street system of the Edo Period castle town was required to incorporate several mutually conflicting cultural concepts and functional requirements which required resolution within the context of the site, climate and specific circumstances of each town. Defence requirements necessitated narrow streets with minimum transparency through the town from perimeter fortifications to castle and road junctions designed to thwart an invader rather than to maximise traffic flows. Hagi’s road structure developed principally in accordance with the internal requirements of the town and its residents rather than in response to a regional or national role. Hagi, by virtue of its isolated position as a terminating point for the regional road system, remained untouched by the pressures of through traffic. In Hagi, the absence of through traffic of any significance resulted in the layout of the road system in accordance with the requirements of the town’s internal organisation.