There ARE ways to make a flight faster than normal, and some airlines encourage it to reduce delays down the chain.

Commercial aircraft are almost never flown to their maximum operating envelopes. They are capable of much more than you will ever experience in them in terms of altiudes, speeds, and manouvering capabilities. They are engineered way beyond their standard uses. They are directed to fly with passenger comfort in mind...taking off like a rocket and banking at 40 degrees makes for filled barf bags...but the aircraft can do it no problem.

Airlines budget flight profiles down to the smallest detail in order to save fuel and keep up with the schedule. Flying an aircraft at full speed consumes huge amounts of fuel, when more can be saved by flying at moderate speeds in higher altitudes. Most airliners will operate most efficiently between 36 and 40 thousand feet, in the range of 450kts.

The routes are also designed for efficency..while it is possible to fly a direct, straight line gps plan to a destination, most aircraft are using high altitude jetways and waypoints that do not have them going in a straight line..especially flights over land.

The pilots will also make attempts to avoid bad weather, while still taking advantage of tail winds..if the plan calls for cruise at 340 but there is a steady, strong tail wind at 380, they will seek clearance to take advantage of it and recalculate their fuel consumption numbers. They are encouraged to save as much as possible.

If a pilot wanted to cut down flight time they could indeed fly faster than usual and take advantage of lucky weather to their backs, as well as get lucky with approach vectors that are more direct and don't involve looping back around..they would also have to have luck with ground traffic and threshold lines. But 1.5 hours is pushing it...most of the time they squeeze out no more than 20 minutes extra. And of course, they would need to burn more fuel than required with I would imagine is not easy with logistics looking over their shoulder. AA claims a full transcon flight really doesn't generate more than 200 dollars in profit when all is said and done. That could be eliminated quickly with speedy flying, considering the cost of jet fuel