The busy roadway had been shut down for the past month from 8:30 a.m. to 7 p.m. so that crews could replace a century-old water main.
The signs weren't changed yet Tuesday night, but Coldwater Canyon was back in business.
"I think it's amazingly great. That's so good. I'm so happy," said Robbie Troy of Studio City.
Tens of thousands of drivers who rely on Coldwater Canyon to go between the San Fernando Valley and the Los Angeles Basin have been forced to use alternate routes.
"It's been extremely frustrating. I work at West L.A., so we always take Coldwater. I've been taking Laurel Canyon so far," said Assad Khan of Sherman Oaks.
In 2009, the massive pipe ruptured, causing $8 million in damage in the area. Even though Coldwater Canyon is open, the construction and some of the restrictions on the road continue.
Cars heading northbound and southbound on Coldwater Canyon cannot turn left onto Ventura Boulevard. But residents say they're just grateful the worst is over.
"We are so excited that that is open because our house is for sale. With the construction there, it's been difficult, so now the house looks like it's going to be sold," said Sharon Butler of Studio City.