The city of Phoenix installed a flashing yellow arrow signal on Seventh Avenue near Roosevelt Street.
The yellow arrow was activated on Thursday, July 14.
A flashing yellow arrow indicates left-turning traffic must yield to oncoming traffic before attempting to turn.
According to research funded by the Federal Highway Administration, left-turn crashes can be reduced by as much as 20 percent with the newly activated yellow left-turn arrow.
Phoenix will monitor the installed yellow left-turn arrow to determine if the city will add more such upgrades around the city.