LIKE MANY OF YOU, we, too, have been suffering through the birth pangs of an expanded Metro system. The frustrations have been enormous - long delays between trains, farecard machines that don't work, broken escalators, missed bus connections (and appointments), stalled trains, uninformed and occasionally rude personnel and on and on. And so, in turn, has the nostalgia been enormous for the good old pre-Metro days. We have been deeply moved by the sentiments expressed in Letters to the Editor about the dependability of the bus service that used to be. But in reading the flood of letters that has come to us, we have been struck by the nostalgia of so many people for the old bus service.

Without meaning to remove any of the pressure on Metro to solve its problems, we would like to jog some short memories. Contrary to the impressions you might get from reading our mail, the buses did not always run on time and complete their runs, passengers did not always have the exact fare, and drivers were not always courteous. We can remember:

Sitting in a bus for almost an hour last January waiting for a traffic jam to break.

Standing on a corner for 45 minutes in the rain when two scheduled buses never appeared.

Moaning bitterly as a full bus passed us by one cold morning.

Putting a dollar bill into the fare box for a 60-cent ride.

Being late for work (and missing an appointment) when a trafic accident blocked our bus passage across a bridge.

Cursing when an automobile splashed mud all over the bus stop and the people waiting there.

We bring these things up because it seems to us to have become quite chic to bad-mouth Metro and call for a return to the old days. Metro does have serious problems - some of them of its own making - and it desperately needs to solve them. It must put an end to this rash of mechanical breakdowns that make riding it risky if you have to be somewhere at a certain time. It must get more equipment into some of its stations. It must do something about its personnel problems. But despite all that - and more - Metro is not the disaster a good many people now say it is, and surely not so large disaster in relation to what preceded it.

Part of the problem is that public expectations of what Metro could do were too high. It was counted on to operate perfectly and to reduce commuting time for all its riders as soon as it opened. Everyone now knows - including Metro's top officials - that making the system operate smoothly is harder than they thought it would be. And everyone now knows that a bobtailed system, like that now running, slows down the commuting time of most of its riders. Some of Metro's problems will be solved in time - at least they'd better be. Others will work themselves out as the system grows; the ride of Alexandria commuters, for example, will be shortened considerably when the trains reach that city and the bridge over the river opens.

In the meantime, let's not judge Metro's performance against that of a bus system that never was. Compare it, instead, with the real one of O. Roy Chalk if you can summon up a memory of those dark days, and you'll find youself feeling better about it almost instantly.