What are the advantages and disadvantages of Manhattan-Style routing?
The primary advantage of a Manhattan route is that it can always be completed. You just need to have enough board area to accommodate all of the traces &mdash; but otherwise, you'll never find yourself unable to complete a route. This can be important if you need to get a layout done on a fixed schedule &mdash; the amount of work is roughly proportional to the number of pins, and you won't spend days or weeks trying to complete the task because of blockages.

Other routing algorithms might be more efficient than Manhattan in terms of board area and the number of vias required (saving money on each board produced), but they cannot guarantee completion of the route in every case, which means that there's a nonrecurring cost risk in terms of the engineering effort required.