I fully agree with The Post's recent editorial concerning the hazards of light-controlled intersections {"It Happened on 14th Street", July 11}. It correctly points out that the change from red to green is a signal to look, then proceed. I have preached a similar message to my children for years. However, I believe more can be done than just issuing verbal warnings.

Consider a typical intersection of A and B streets. During a cycle, the light will be red on A and green on B. The green light will turn to yellow for approximately five seconds, then will turn red, while it remains red on A. I would point out the interval during which the light is red in both directions. This interval, which we can call the "double red," is the only period during which it is clearly illegal for cars from either direction to enter the intersection (right turns aside).

Using a digital stopwatch, I have timed the "double red" at some 100 intersections in the past year, mainly in Montgomery County, Fairfax County and Northwest D.C. At one intersection in Virginia, the interval was 3 seconds. All the others were less than 1.2 seconds. Under these conditions, it is therefore possible for a vehicle on street A to enter the intersection while the light is still yellow and to collide with a vehicle on street B that enters as soon as the light is green. Neither would break the law, so enforcement efforts would be pointless.

Rather than resort to education alone, why not increase the "double-red" time? A 5 to 10-second "double-red" interval would result in a clear intersection before traffic resumes. Coupled with rigorous enforcement, which would then be feasible, such a change could eliminate a deadly traffic hazard. JOSEPH C. FRATANTONI Rockville