"It needs it. It needs it. Traffic can be pretty horrendous. It turns into a parking lot more often than not," said Harriman, a regular 405 commuter.
Right now, the 13-mile stretch from the 73 to the 605 has four regular traffic lanes and a carpool lane in each direction. Total width: 177 feet.
Orange County Transportation Authority officials proposed to widen out to either 212 feet by adding one more regular lane, making it five lanes in each direction; or widen to 236 feet by adding a regular lane and an additional carpool or express-toll lane. In order to do that, 11 homes would have to be removed.
Some O.C. residents have concluded you can't build your way out of the traffic mess, but others feel it's the only way.
"They know that there's going to be more cars 10 years down the road, so why didn't they do it then when it was cheaper?" said motorist Joan Fowles.
If Orange County widens the freeway, there's still a problem: L.A. County says it has no plans for a 405 makeover, so any traffic in the future that comes flying down the 405 would come to a screeching halt at the county line.
It's already happened in Buena Park, where Orange County is rebuilding a much wider Interstate 5 while L.A. County gets by with an old four-lane freeway. L.A. is planning a major widening, but it's still years from completion.
L.A. County Metropolitan Transportation Authority General Manager Art Leahy says both counties are outgrowing freeways and are looking for alternatives.
"In Los Angeles back in the '70s and '80s, I don't think that we thought of ourselves as a big city. We were a big town," said Leahy. "At some point, when the environment became constrained and built out, we began to look at more rail lanes and things of that nature. Orange County is beginning to feel the same crunch. It will be very difficult for them to build any new freeways. That's where L.A. has been for some period of time now."
Leahy says L.A. County may improve connections between carpool lanes at the county line, but won't add lanes to match O.C.'s improvements on the 405.