Flashing yellow arrows

Safety issueYellow arrows

Left turns are the most dangerous movement a motorist makes so successful left turns are critical to the safe and efficient operation of signalized intersections. Motorists need clear and consistent messages to move safely through an intersection. Due to the wide variety of left-turn signals in use around the country, there was a need to establish a consistent message.

Safety design

The Federal Highway Administration has adopted the flashing yellow arrow as a national standard. In most locations the flashing yellow arrow is part of a four-arrow arrangement within a signal located over the left turn lane. The new flashing yellow arrow provides a more direct message for left turns: left turn is permitted, but driver must first yield to opposing traffic and pedestrians, then proceed with caution.

The arrows in a four-arrow signal indicate:

  • A steady red arrow means drivers turning left must stop.
  • A steady yellow arrow means prepare to stop.
  • A flashing yellow arrow means a driver may make a left turn if there is no oncoming traffic and there are no pedestrians crossing the street.
  • A steady green arrow means a driver has the right of way to make a left turn.


  • A national study found flashing yellow left-turn arrows are easier to understand than traditional yield-on-green indications, reducing crashes by 24 percent.
  • In certain cases, the flashing yellow arrow can allow for more opportunities to make a left-turn.

Where are they being used?

  • Flashing yellow arrows are a new indication for signalized intersections that may be used depending on operating conditions and time of day.
  • Existing signalized intersections can be retrofitted to convert from traditional yield-on-green indications to flashing yellow arrows.

Additional resources


David Karnes, P.E.​
WisDOT Traffic Systems & Management Chief
(414) 220-6804