Since waiting for some Washington traffic lights to change is like waiting for Godot, a little advice may be in order: if you're stopped more than a minute, you may be excused. The light is broken.

Such are the tidings from John McCracken and Andre Robinson, producer and director respectively of stoplight follies in the nation's capital, where their red and green-eyed players increasingly need prompting.

As the electromechanical infrastructure crumbles around them, victim of old age, obsolescence and deferred maintenance, they would like you to know they are doing what they can.

You say your red light sticks on Benning Road every morning and you can't get out 16th Street at night because a left turn blinker won't go green? Listen, they know.

And nobody comes to fix it for days at a time?

Hey! Robinson, the traffic service manager, has six men--just six--for maintaining the city's 1,250 traffic signals at a time when 60 intersections can go haywire during a single rush hour. Ten years ago, when the system was younger, stronger and less prone to nervous fits, the city had 18 men to maintain it.

Add to that the fact that those six provide intensive care for equipment produced by 69 manufacturers, few of whom make even the parts any more, and you get a small idea what we're up against here. You're lucky to get to work at all.

McCracken, the 29-year-old traffic engineer, who heads the city's office of traffic signals, says the 30-year-old stoplight system, once a workable, state-of-the-art affair, is like a worn-out pocket watch.

"It's mechanical," he says. "It's signal timers run on wheels and gears and motors, all of which wear out. Nobody makes that stuff any more."

The key features are not the lights and bulbs themselves, but centralized controls that time them off and on. The brains for each signal lie within a metal control box at the intersection, wherein pedestrians can hear muffled whirrs and clicks as "Don't Walk" changes to "Walk."

Each signal is programmed individually for its local conditions on cycles that range from a total of 80 seconds to 120 seconds for the full round of red-green-yellow, turn arrows and "Walk-Don't Walk" signs. Only a handful of complex intersections have the 120-second cycles, and in no case is a light supposed to stay red more than a minute.

Each signal can handle three programs: one for morning rush, giving priority to traffic flowing into town; one for evening rush favoring outbound vehicles, and an off-peak cycle for balanced flow.

When it's time to shift from one cycle to another, a transmitter at Fort Reno Park off upper Wisconsin Avenue sends a radio tone to about 40 "master" intersections, linked by cable to "slave" intersections in their neighborhoods.

This works well enough when it's working, but Robinson and McCracken say the radio network, too, is not without its problems.

First of all, the radio signal can be confused or blocked by everything from birds and planes to the topography of the city. The lights along Canal Road, for example, malfunction often, the two men say, because they stand close beside a roadside bluff, which makes radio reception difficult.

Secondly, the restriction to three preset programs makes it difficult to deal with altered local conditions, such as wrecks, snow and ice, and the like.

Thirdly, and most important, there is no way for engineers at the central control office to know whether any stoplight has received its appointed signal and is operating properly. Until the first irate motorist calls.

However, help is on the way. The city is moving to a new computerized system, solid state electronics, as proved and reliable as a digital watch.

Other cities--Charlotte, N.C., is one--have such systems, McCracken says, and they work.

Under the new system, malfunctioning stoplights will signal their infirmities to a central office, where engineers will then be able to throw switches manually to adjust other signals in the area to deal with the backups, until a repairman can get on the scene.

In addition, the system, to be financed by $34 million in federal funds, will provide for more flexibility in preset programs and will do away with radio entirely.

"We just have to go pop a few manholes and figure out how to pull 180 miles of copper wire through the duct space under the streets," McCracken said.

The new system, already in the development stage, will take five years to install, McCracken said, though parts of it will be working in the downtown area in the next two.

Once installed, it is expected to cost about $660,000 a year to operate, a figure that includes some funds for rebuilding an inventory of parts. "The trick will be persuading people to spend the money to keep it up," McCracken said, "but I think the awareness is coming."

Meanwhile, Robinson labors with ingenuity and humor to keep the existing lights blinking, mindful of that day in 1987 or so when, weather and traffic permitting, the long-suffering citizenry of the District will be able to wing down Pennsylvania Avenue at the lawful limit, hitting green lights all the way.