In a recent column about traffic signals, I'm afraid I made some rash statements about turn arrows.

I said that where there are no signs prohibiting turns, a full green light permits them, provided the turner yields to pedestrians or other vehicles that are legally within the intersection. I added that a green arrow, on the other hand, is indication of an "exclusive" or "protected" movement in which the driver needn't worry about yielding. Vehicles and pedestrians that might otherwise conflict with his turn have been halted.

Woe is me! Unfortunately, I failed to add a disclaimer. I should have inserted, "At least that's the theory behind the uniform traffic code that is supposed to be followed by every municipality."

Andrew C. Teter brought me back to reality with this note: "In the District of Columbia, a green right-arrow at the entrance to a traffic circle does not necessarily mean that the motorist's turn is protected. Traffic within the circle may also have a green light at the same time. This is true at Dupont Circle for instance.

"I think the green arrow in such cases is misleading and dangerous, and the more so because some other circles in the District have a yellow arrow for the same situation.

"A reasonable person not aware of the danger, especially a tourist, might assume that the green arrow gives him an exclusive right to proceed."

You are so right, sir. The mess at Dupont Circle is inexcusable. Our Highway Department engineers have long acknowledged that the signal system there is unsatisfactory. Yet the instalation date for a new signal system has been postponed repeatedly over a span of more than three years - and I still can't find out when we can expect it.

Incidentally, Leora A. Richter writes, "I have another traffic arrow puzzle for you." She refers to installations such as the one at 14th and E Streets NW.

A northbound motorist who looks at the signal that faces him from the right curb sees a full green light. But if he looks at the signal that faces him from the left curb, he sees a green straight-arrow.

So while the signal on the right says he may turn, the signal on th left says he may not turn.

If the motorist turns, he risks getting a ticket because a straight arrow means one can proceed straight ahead only. If the motorist knows that eventually a green left-arrow will appear, he may wait for it. The deivers behind him will immediately begin honking.

Where is the common sense in a signal system that gives motorists two conflicting signals simultaneously?

The whole idea of the uniform traffic code is standardization that will permit a motorist from one state to know what signals mean in another state. Yet in a city that hungers for tourist business, we greet our visitors with a system that varies from one intersection to the next.

People who have lived here for years aren't sure what our signals mean, but strangers are expected to cope with them. It's absurd.