The only reason a human will not give you a nonsense bridge is that a human is running a 2.5kWh spacial physics calculation engine in his/her head.
Replace 3.js with an engine that embeds physics, ask it to do test fly-through through each city and fix inconsistencies and let's then compare the results.
Replace 3.js with an engine that embeds physics, ask it to do test fly-through through each city and fix inconsistencies and let's then compare the results.