This freeway acts as bypass of Downtown Los Angeles. However, it is not always faster. In fact, 10 am can look just like 10 pm traffic-wise any day of the week. This freeway more or less invented the 24 hour rush hour. There is a joke that it was numbered the 405 because you are going 4 or 5 miles per hour. This route has HOV lanes along its entire route, with the last section completed being through the Sepulveda Pass. New “Express” lanes are currently (2021) being added between State 22 and State 55. When complete, the 405 will have two HOV lanes in each direction between those points and SOV vehicles will be allowed to enter through a tolling system. I-405 was completed in sections between 1956 and 1968.
Orange County
405 North from the HOV lane in Irvine. Note the wide dirt median, buffer zone to the right, plus four mixed lanes. This is a wide freeway indeed.
Direct HOV ramps at the 55 connecting 405N to 55N. There are also connectors from 55S to 405S.
Signage for the 55 North HOV connection
Along the section cosigned with the 22, newer “Boulevard” style lights have been installed, giving this section of the 405 a very unique look.
Los Angeles County
At the 710, greenout for State 7 is still visible.
405 south at the 110. Many overlays here with the Carpool lane formerly ending here and the 110 used to be State 11.
Signs placed at certain exits along the 405 from LAX to Sunset Blvd. This section of I-405 is the most congested. Alternate I-405 and I-10 shields have also been placed at Wilshire Blvd and Sepulveda Blvd.
Here, I-405 meets SR-91. This far west, SR-91 is a surface street – Artesia Blvd. Also note the older 107 shield for Hawthorne Blvd.
Old sign near Waterford St, heading northbound. There used to be three or four of these blank signs until the early 2000’s.
1957 ACSC map showing the first segment of the San Diego Freeway (then State 7)
The Mulholland Bridge over the 405 at the top of Sepulveda Pass. View is southbound.
From California Highways and Public Works November/December 1960.
Old signage approaching US 101 heading over Sepulveda Pass. Note the outline US 101 shield.
The US 101/I-405 interchange signage. The US 101 sign has no button copy on it.
Southbound San Diego Freeway at the Ventura Freeway on August 20, 1958. Note the signage for SR-7 instead of I-405. This would change only a few years later. Courtesy – Caltrans
The 405 at the 118. Devonshire St. is the former alignment of Rt. 118. Note the lack of striping on the thru lanes. Only Botts Dots here.
Mileages to the larger cities in the area. This one is in the middle of the San Fernando Valley. Bakersfield is the former control city of the 405 northbound.
Original signage at the 5 / 405 split. Note the US 6 signage. The 405 overhead was still there until a few years ago. Courtesy – AASHTO
Overhead signs at the old south end of the Golden State Freeway. Bridge at center is the San Fernando Road OH. This is the 1955 version of the I-5 / I-405 Interchange. Courtesy – Caltrans
One of the few remaining signs for the named freeways in LA. This one is at the north end of the 405.
The north end has an END marker.
North end of the 405 at the 5. Truck lanes are at right.
