Last night I used a prepurchased token to ride the New York subway and later a buff-colored pasteboard ticket to ride the Metro-North Commuter Railroad from Grand Central Terminal into Westchester County on a weekend trip into that area. The farepaying arrangement may be archaic, but it works.

But New Yorkers had best beware. After the six-week Metro-North strike was settled a few days ago, the head of the Metropolitan Transportation Authority said there are plans in the works to test Washington-style Farecards on both the subway system and the MTA's two commuter railroads.

On the commuter railroads, it makes some superficial sense, since their fares already are based on the time and distance of travel. But we suspect that MTA's hoped-for reduction of trainboard ticket-collecting personnel would be more than offset by the need for agents at stations that now are unmanned, not to mention a huge investment in station security hardware.

And Farecards on the Big Apple's subway? New Yorkers should be forewarned that it could lead to an end to the citywide flat fare, now 75 cents. A ride to Queens or the distant reaches of Brooklyn could skyrocket. Not to mention the chaos when, say, 28 of the 35 Farecard vending machines we can imagine at Times Square station would be simultaneously on the blink or started rejecting dollar bills. Wow!

Bulletin: At the Silver Spring Metro station at 9:45 a.m. yesterday, only one of the 10 Farecard-activated entrance gates was working.