Have you ever tried Specctra autorouter guys?
With its excellent auto place and autoroute capabilities, no human can match its speed.
You can include your own design rules and you can command it to make tracks of equal lengths for high speed buses which is very difficult for a human to do.
You also split the boards into rooms with certain characteristics such that components with certain heights can be placed etc..., you define nets with certain track widths right into your schematics, i.e power track width is 40 mils.
Some of the very complex PCBs can be routed by humans but they take months and prawn to lots of errors, while Spectra does the job in few hours.
Ofcourse you use your experience to clean up afterwards because no auto routing program is perfect, but you need very little cleanup after specctra.
The gap between Specctra and its competitors is so huge that no one even comes close to it.
The only drawbak is its price, as far as I remember it costs 100,000 $ or so.
Mahmood