How Long Will It Take For Sad Sack Sentimentalists To Mourn Not Having To Lean Over The Platform To Search For Headlights On Faraway Tracks, Noting The Telltale Scurrying Of Rats Or Straining To Hear The Plaintive Click Of A 100-Year-Old Switch?

Amazingly — considering the time, effort and heartache for L riders — the electronic thingamabobs that tell you how long it will take for a train to arrive actually work:

Subways future and subways past seemed to collide on a recent morning at the Jefferson Street station on the L line in Bushwick, Brooklyn. New electronic signs on the platforms showed how many minutes a person would have to wait until the next train: at this moment it was eight minutes for a Canarsie-bound train and four minutes for a Manhattan-bound train.

But the recorded female voice on the public address system that was supposed to work in tandem with the signs was showing signs of a breakdown: “Ladies and gentlemen, the next L, the next L —,” it said over and over, like a scratchy recording.

The signs and the recording are part of a new system being tested on the L line that will, for the first time, give riders accurate information about the arrival time of trains, coupled with clear announcements — both things that seem as foreign to the subway as a man offering a woman a seat on a crowded train.

On this day, however, the signs worked like a charm. A stopwatch revealed that the trains came and went as predicted. It was almost unnerving.