Does a creature with Improved Trip get a free attack against Driving Attack's victim?

Question

The feat Driving Attack has as its Benefit

If you use a full-round action to make a single melee attack with any piercing weapon and succeed in hitting, you can initiate a special bull rush attempt against the target. This bull rush uses your total bonus on damage rolls in place of your Strength modifier. You do not provoke an attack of opportunity with this bull rush, and you cannot move forward with your opponent.

If you succeed in pushing an opponent back 10 feet or more, you can reduce the distance you push him by 10 feet. In return, your foe falls prone in the square where he ends his movement. Note that by reducing the distance you push your opponent, you can have him fall prone in his current space. (Player's Handbook 2 76)

Does the opponent falling prone trigger the extra attack from the feat Improved Trip (PH 96)?

Answer 1

No.

Improved Trip is pretty clear as to what triggers the free melee attack:

If you trip an opponent in melee combat, you immediately get a melee attack against that opponent as if you hadn’t used your attack for the trip attempt.

At no point is a driving attack a trip maneuver as per the rules of the game. Even in the fiction: Driving a spear into someone and pushing him to the ground is not exactly "tripping" him.