Northbeach,
You've already been given the good answers. It is called "metering" here in the States and it would work. As a matter of fact, we could make it work right off the ground. If...
All pilots would fly at the speed listed in their flight plan.
Airlines only flew one type aircraft.
There were never any thunderstorms or other weather.
Departures could sit "in position and hold" for a precise time to depart.
Of course, with the first go around, the first blown tire, the first missed high speed taxiway -- the whole day and the whole plan would be shot.
Not to worry though. The eggheads will keep talking the managers into spending billions of dollars by telling everybody that it will all work -- someday.
Don Brown