I thought that exact same thing the first time I saw this type of town drawing, but in fact the lining of the road method appears to have been typical in the medieval towns of England, at least. Look at John Speed's set of early 1600s maps for examples:

http://faculty.oxy.edu/horowitz/home...ed/Cities1.htm

From Speed's depictions we can see that "road lining" was true of even large towns/small cities such as York, but not of large cities such as London wherein buildings are crowded together into true city blocks.