This study aimed to clarify the method for the design and alignment of streets in the Tokaido Road during the Edo period (1603-1868). For the analysis, I selected 24 streets in 53 station towns in the Tokaido Road. These streets still reflect the same straight alignments created before its adaptation into modern town planning. My findings indicate that the alignment of the Tokaido streets was closely tied to the surrounding terrain, such as mountain summits. I believe that the relationship between street design and surrounding mountain landscapes will be useful for future discussions of regional landscape planning.