A glitch during a routine traffic light software upgrade was the cause of flashing red signals at multiple intersections citywide on Saturday morning, according to the New York City Department of Transportation.
The agency dispatched crews to restore traffic lights back to normal, and as of 11:20 a.m., more than half the malfunctioning signals were back to full operation, a DOT spokesman said in an email.
This is the first time that the DOT has encountered this kind of signal disruption after a software upgrade, which takes place periodically on weekend nights, the spokesman added.
Drivers were advised to come to a complete stop upon encountering a flashing red signal.
“Proceed when you can safely,” the DOT tweeted Saturday. “Always give pedestrians the right of way.”
The agency did not say how many intersections in total were affected.
On Sunday morning, the DOT tweeted that all signal issues had been addressed.