LAST WEEKEND seemed meant for bicycling. As we were enjoying one of the area's new trails and wishing there were more of them, we got to thinking - as we do every spring - about bicycling to work. It was an attractive thought, made even more so by the patriotic feeling one could get from responding so well to President Carter's plea for energy conservation. That is, it was an attractive thought until we remembered the traffic, the fumes and the thieves. Then we thought about thos people who biked to work last Friday in honor of Bike Week, and we felt a certain admiration for their courage in the face of such adversity.

After a while, as we kept reflecting on the matter, we thought about Metro and all those shiny, new stations. Would the bicycle commuting traffic pick up if it became possible to park one safely at a subway stop? The more we thought about that, the more we began to believe it could happen. Of course, the pleasantness of the day had something to do with it; the thought never crossed our mind during those bitter winter months. But a little checking revealed that Metro has had a lot of thoughts about it, too. It has a bicycle coordinator, a study conducted along with the Council of Governments on the potential market for bicycle commuting and a plan to put in some bicycle lockers if somebody will come up with the money for them. In fact, the District governments in both Virginia and Maryland about lockers at ome of the suburban stations.

A bicycle locker, it turns out, is fairly expensive. Metro doesn't know the exact cost yet but it is likely to be the $300-400 range. With a rental charge of $5 a month, which is what is now planned, the capital outlay won't be recouped for five or six years. That got us to wondering about bicycle parking lots of check stands, perhaps as adjuncts to auto parking lots or existing businesses. We don't know whether there is a pontential market large enought to support either, but there might be, particularly if the President gets his way in making the costs of driving a car subtantially greater than they now are. The people we see out there on the bike trails on weekends are mostly not the type who would ever dare to brave the traffic on area highways, as bike commuters must now do.

But some of them might be enticed - at least in good weather - to pedal on bike trails like the ones that lead to Rosslyn and National Airport or on neighborhood states to a subway station. It is an idea worth thinking about some more.