It could be the transmission, it could be some parts under the vehicle that rub only when travelling forward.
Your gear linkage is offset!! Or you are on a steep down hill
Dust, unevenness.
Engine idle too high.
Generally new pads will contain a layer of dust which causes the initial squealing. The squeal should go away after a bit if driving.
Turning the steering wheel farthest left or right for a few seconds will cause a loud squealing.
check your wheel bearings
The most common cause is slipping belt
The cause of the squealing sound is because you are turning the steering wheel completely to the right or left
If it "locks" when youre driving, then its for your own good. Most (if not all) auto-trannys can be put into neutral while going forward, but they cant be put in reverse unless you have the break pedal pressed all the way down.
A reversible process is one which can be reversed and causes no changes in the system or surroundings. For a process in equilibrium, the rate of the forward process equals the rate of the reverse process (which can be, but is not necessarily equal to zero).
it could be a serpentine belt or accessory belt.
Sounds like your belt may be worn out.