ON GT Road.
One can go as fast as he/she can after magrib,coz police on GT road dont have night vision camera's.I myself have travelled at 100 in a 70km zone lot of times,but late at night around 11:00 PM+ with almost no traffic on road.But the problem is that GT road is not safe for driving fast,coz of inter city traffic and heavy traffic.So i wouldn't advice anyone to go beyound 120km/h on GT road at night.
ON Motorway,there are 3 point where u'll find police 24/7,either going on coming
1 - After chakari
2 - kalarkahar
3 - After beihra and sometimes before beihra.
So stay within speed limits in these area's.As for night vision camera's they only use radar guns at night,so if u somehow make a device to change number plate then u might be able to ditch them.(something like in transporter-2)