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Telling a Story Through
Highway and Planning Maps

Southern California Highway Renumberings
(Illustrated through Maps)

[1964 Sign Change Image]
Figure 1. Caltrans Crews Changing Route Signs in 1964
(Photo from the cover of California Highways and Public Works, v. 43, n. 3-4, March-April 1964. Photography by Peter Asano.)

As described on the Route Numbering pages, California originally had two systems of numbering highways. The first system was the legislative route number (LRN) system, which was used by the legislature and the state highway department to refer to highways. The second system was the signed route system, which consisted of state (white spade-shaped shields) and US highways. Figure 2 shows how the old system looked in Southern California.

[Thumbnail: 1959 Map]
(Click on image for a full-size map. Full-size image size: 284K)
Figure 2. Los Angeles and Vicinity
(Map excerpted from the 1959 Rand McNalley Road Atlas and Radio Guide, currently out of print. The map is found on pages 58-59.)

It is interesting to compare the old system to the new system. Note the lack of the now-familiar Interstate shields. In 1959, I-405 was State Route 7; I-5 was US 99 or US 101; I-10 was US 60/70/99, I-701 was State Route 15, and I-110 was State Route 11. Other non-freeway routes also had different numbers: present-day Route 91 was Route 14 and Route 18; present-day Route 14 was Route 7. Some numbers, however, are the same to today: Route 27, Route 39, Route 22.

The system got even more confusing when the legislative numbers were brought into the picture. Figure 3 shows the Los Angeles and Vicinity inset map from the 1963 state highway map. The numbers in squares represent the legislative route numbers; the numbers in shields represent the signed route numbers. Note how a single signed route number might have many legislative route numbers. This made references to routes confusing.

[Thumbnail: 1963 State Highway Routes]
(Click on image for the full-size map. Full-size image size: 208K)
Figure 4. Excerpt from the 1963 State Highway Map showing Los Angeles and Vicinity

On September 20, 1963, Senate Bill 64 became effective. This possible called for a renumbering of the state highways. The state shields were changed from black letters on a white background to white letters on a green background. Why the color choice? California Highways and Public Works says:

The colors were decided upon after a panel of engineers had checked various color combinations in over-the-road tests. Blue and gold were strong contenders but lost out when it was discovered that gold had the tendancy to appear muddy at night while the white and green retained their true hues.

Figure 5 shows the effects of this renumbering in Caltrans District 7. It shows both the old and new legislative route numbers, and uses color to show route continuity.

[Thumbnail: 1963 Renumbering]
(Click on image for full-size map. Full-size image size: 176K.)
Figure 5. 1963 District VII State Highway Numbering Map

The 1963 maps are interesting for some of the highways that they show that no longer exist. Many of these highways were short routes created until the freeway system was established, and represented older routings. The following are some examples of these:

Others routes represented planned freeways that were never constructed:

A few years after the renumbering, a lot of the temporary bypass routes were deleted (Route 42 was deleted at this time, but continues for some reason to be signed by the state and show up on maps). By 1986, the system was much closer to what we know today. Figure 6 shows the 1986 system. Routes shown with routes in open circles were never adopted. The lines with open dashes are currently under construction or construction is planned.

[1986 LA Map]
(Click on Image for the full-size map. Full-size image size: 282K.)
Figure 6. Excerpt from 1986 State Highway Map showing Los Angeles and Vicinity


The following maps scanned in by others also provide information on Southern California highways:

<- Southern California Freeway Development - 1960s and Beyond -> San Francisco Freeway Development - The City

© 1996-2020 Daniel P. Faigin.
Maintained by: Daniel P. Faigin <>.