It's going to be some tricky driving around the Westwood and Brentwood area. The Sunset Boulevard off-ramp on the northbound 405 Freeway will be shut down for four months.
The official closure was scheduled to begin at midnight, but the traffic impact started earlier.
Caltrans crews will be building a new, larger off-ramp with two right-turn lanes and one left-turn lane. It will also be able to accommodate more cars than the current off-ramp.
So far, this project is a year delayed and $75 million over budget.
Residents from the Bel Air area say they are disgusted when it comes to all the construction.
"I am frustrated beyond belief with this project. It has been a nightmare," said Diane Houle.
"It's made my life tough, especially at night when they close it down," said Ken Kraft. "Last night, it took me an hour to get home, and it should have only taken me 10 minutes."
"We actually live right down the street, and we've been dealing with the traffic for a good year or so," said Aimeen Aiyoud. "It's been incredibly difficult. We're being patient because we hope it's going to be better."
Metro recommends using Wilshire Boulevard or Moraga Drive to get around the closure. Detours will be different day to night, officials say, and Sepulveda Boulevard in the area will be closed.
The goal of the project is to ease the northbound congestion exiting Sunset Boulevard. With thousands of commuters using the off-ramp daily, traffic during rush hour can back up all the way to Wilshire, and sometimes as far back as Santa Monica Boulevard.
And in three weeks, the eastbound Wilshire on-ramp to the northbound 405 Freeway will also be closed for three months.