For many years, an old traffic signal, including a control box with a revolving wheel, has controlled traffic at 18th and Main streets/Boulder Drive in Tulsa. The "clicks" heard from the control box come from the wheel hitting switches that change the traffic signal's colors. The intersection has a left-turn signal for westbound traffic that has corresponding green right-turn arrows on northbound Boulder Drive traffic. When the left-turn signal cancels, the solid yellow light comes on and then cancels to leave a only red light. The red lights always are on for this direction. Until the fall of 1981, green arrows existed on 18th Street. At that time, eastbound traffic had a straight-right green arrow configuration, while westbound traffic had a straight-left. New signal heads were installed for eastbound traffic and northbound traffic on the northeast corner, which maintained the same configuration. The eastbound green arrows became solid green lights, while the westbound green straight arrow also was converted to a solid green light. The left-turn arrow remained intact. Nothing was changed for Main Street or Boulder Drive. The Boulder Park Apartment building stood on the northwest corner until it was demolished in 1982. Photograph taken May 5, 1984.
