Which geographic factor drove columbus to search westward for a route to east asia?

Basically it was length. The traditional route eastward to the East Indies was really, really long and in order to reach it more efficiently and more cheaply Columbus decided to go westward with the notion he would accomplish this. But he miscalculated the size of the Earth and that led to many problems on his voyage.

Louis xvi wanted to force aristocrats to pay taxes for the first time