Old style US 101 shield US 101 Photo Gallery

City of San Diego (1940 - 1958)

Pacific Highway

US 101 was modified considerably during and after World War II. During the war, San Diego was an important location due to the naval presence and the concentration of war manufacturing. Even after the war was over, San Diego continued its incredible growth. Fortunately it was realized that an extensive road network was required and during the late 1940s and 1950s portions of US 101 became some of the first sections of highway to be brought up to full freeway standards in the county. Two major upgrades, occurring in 1942 and 1958, demonstrate the evolution of the road.

1958 Extension

By 1942, Pacific Highway between Barnett Ave and Rosecrans Ave had been upgraded to partial freeway standards. While this was a much needed improvement, it was not until 1958 that the limited access portion was extended south of Barnett Ave. The extension was short, however. It only went for about a mile south, with the major improvement being the grade separation over Washington St. This portion saw service as US 101 for seven years until it was superseded by I-5 in 1965. Unlike many other abandoned freeways in California, this one still has the bulk of its original signage and offers an interesting look at what signs looked like at the time


Pacific Highway entrance sign
Pacific Highway / Washington St. grade separation

Above: Original entrance to Pacific Highway. The sign is obviously new, but the poles are original.

Left:   Flyover ramp to roadside businesses.

Below left:  Original sign indicating roadside businesses - sign is white on black.

Below:  Old overhead sign for approach to Barnett Ave. Unlike modern signs, this does not use button copy. The sign on the right used to say "101 Los Angeles" with two arrows indicating the lanes for through traffic.

Roadside Business Sign Pacific Highway overhead sign

1943 Highway Modernization

As mentioned in the previous section, in 1942-43, Pacific Highway north of Washington St. was upgraded to partial freeway status as part of the war effort. During the second World War, San Diego played a major role in supplying war materials and a good network of highways was essential. At the same time, it was also critical that war materials be conserved, which led to the minimalist design of the interchange structures.Contractor's Date Stamp - 1942

Right: Pedestrian overcrossing built in 1942 to facilitate access for workers at the nearby Convair plant.

Left: Contractor's date stamp.

Convair plant pedestrian overcrossing


Barnett Ave. underpass Barnett Ave. underpass with 1942 date stamp

Above: The Barnett Ave. underpass, built in 1942. This was built with the need to conserve materials for the war effort, which is why it has the wood guardrails. It is almost identical to the bridges pictured below.

The picture below accompanied an article in the November/December 1943 volume of California Highways and Public Works titled "Modern Design Features Mark New Highway Construction in San Diego."

US 101 and Rosecrans Ave., 1943
"Overpass structure at cloverleaf grade separation of U.S. 101 and Mission Valley highways in San Diego."  (Caltrans)

US 101 and Rosecrans Ave., 1997
Same location, 1997.
Note: The white wooden guardrail was replaced by a more austere concrete and metal rail in 2000.

Mission Valley (US 101 / US 80) Interchange

The pictures below show the evolution of the US 101 / US 80 interchange, which was built in 1942 as part of the wartime project. By this point, the US was completely involved with World War II and wartime activities had first priority for the allocation of resources. This interchange, originally called the "Mission Valley Interchange," reflects the scarce resources allocated to highway construction in many ways, including the design. For example, one of the cloverleaf where one of the circle ramps was smaller so that the ramp carrying traffic heading from north 101 to the east highway could join with the mainline bridge over the railroad. At the time there was actually a lot of value in the materials saved by not building the extra bridge solely for the exit ramp. In 1961 the interchange was essentially unchanged since its construction in 1942. As the picture above on the right shows, this was entirely removed in 1968-69 to accommodate the newer I-5 / I-8 interchange. The picture to the right is especially interesting since it shows the old interchange in relation to the more recent one. By the time this interchange was under construction, I-5 was already completely eight lanes between National City and San Clemente; this was the last portion of old highway. This is visible in the picture with the completed eight lane I-5 visible at the bottom of the picture and again just beyond the San Diego River crossing.

101-80_1961.jpg (35485 bytes)

Construction of the I-5 / I-8 interchange (1969)
Above: I-5 / I-8 under construction, early 1969. Note the
continued use of the older interchange.
Left: The US 80 / US 101 interchange in 1961, before
they became Interstate highways. (Caltrans)

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Mission Bay Freeway

US 101 (I-5) Mission Bay Fwy in 1956 The Mission Bay Freeway was a short four lane full freeway bypass built in 1954 to help alleviate traffic at the crowded interchange with Balboa Ave / Garnet Ave. It also afforded a savings in travel time by continuing in a straight line rather than swinging out as the older (1930s) alignment had. In 1969 the original pavement was removed and the freeway was realigned to accommodate the new eight lane freeway. However, all of the original bridges still exist, though they were widened. In fact, the one over Rose Canyon Creek still has the original curbing in the middle, complete with the reflectorized divots. (Fun fact: In 1999 Caltrans rehabilitated the deck of the Rose Creek bridge, where as a fop to the previous design, they built the new center divide with the same divots in the curb.)

Left: Mission Bay Freeway, 1961. The freeway bypass is to the left while Mission Bay Drive (Old US 101) swings out to the right. (Caltrans).

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If you have any questions, comments, or if you would like to send me any updates or pictures, please contact me at: casey@gbcnet.com.