TRAFFIC SIGNALS - SOLVING A LEFT TURN PROBLEM

POSSIBLE YELLOW TRAP SOLUTIONS:

• PROHIBIT LEFT TURNS ON CIRCULAR GREEN
  Use red arrow to prevent permissive turns
• RESTRICT THE SIGNAL SEQUENCE TO LEADING LEFT TURNS
  Left turns must go before oncoming circular greens
• USE SPECIAL CONTROLLER BOX LOGIC
  Prevent circular greens on the same street from ending separately
• DIVERT LEFT TURN SIGNAL DETECTORS TO ADJACENT CIRCULAR GREENS
  This would happen when the oncoming circular green is lit
• DALLAS PHASING (no longer allowed by federal standards)
  This showed a louvered circular green to left turns.
• FLASHING YELLOW ARROWS
  Separates permissive left turn control from the circular green

PREVENTING YELLOW TRAP