Nope... not the way I meant it. For the first and second optimizations, you would limit the lat/lons to the following yellow square.
That would be a bit conservative and would cover even the adventures of "Wrongway Peachfuzz" :-D. If you really want to narrow it down quickly, you can use the more radical "mid point" approach as follows (again, use the yellow square limits):
--Jeff Moden
Change is inevitable... Change for the better is not.