When looking for old highways, there are many clues you can use to help discover where old highways ran. This will serve as a partial guide to finding those clues and figuring out the history of a roadway in California.
State Highways
When you are looking for clues if a roadway you are on is an old State Highway, there are a few things to look out for. Depending on the age and location, look out for Right of Way monuments. In California, these are small concrete blocks with a C on the side of them, facing the roadway. They tend to be at the fence line along roadways, at the same distance as the utility poles, or further out. How much they stick out also varies. Some are just a few inches above the ground where others are about a foot high. Look out for these monuments at the beginning or ending of a curve usually about 50-100′ from the centerline of the roadway (or former centerline). For more detailed information on C-monuments, click here.
Old C-Monument State Highway Right Of Way marker from 1930.
Other clues tend to be tougher to spot but can be very subtle in appearance. Roadways that were formerly paved with concrete instead of asphalt are usually cracked in a very specific way if the asphalt is old enough. Expansion joints in the concrete, potholes exposing the old paving, or a defined crack running near the roadway edge usually give this away. Older concrete paving was either 15′, 18′, or 20′ wide. Modern roadways are usually 24′ wide, with two 12′ lanes. Look out for this concrete at curves which appear to have been straightened.
Original alignment of the Ridge Route at Tejon Pass. These lanes were built in 1923 on top of the original 1919 Ridge Route concrete.
On some roadways bypassed or abandoned after 1964, old postmile markers can be found. These markers are similar to the ones on current State Highways. On a current roadway with R mileage, look for old alignments in the area. R mileage indicates a realignment that took place after 1964, which is the point of “base mileage” for California State Highways.
This milepost was found near Whitaker Summit on old US 99. US 99 was gone legislatively in 1964 so Route 5 took over the numbering here. That is why it shows the mileage for I-5.
Abandoned roadways are tougher to spot depending on the area climate. Drier climates tend to preserve older paving better than wetter climates. In some areas, the paving itself was removed after the roadway was bypassed. I have found a few sections of roadway relatively intact, complete with old striping, in central and eastern California. When the pavement has disintegrated or obliterated, you can look out for areas where there is less vegetation and distinct roadway grade. Sometimes old drainage culverts and bridges are left behind with nothing but dirt grade leading to them.
More paving, both lanes now visible.
In any area, make sure to take plenty of photos if you find an old alignment. You never really know when the local jurisdiction will come along and either obliterate or repave the roadway. This is fairly common in Los Angeles County as I have found. The most recent loss has been the three lane concrete in Gorman from June 8, 1933 along old US 99 which was repaved in the past couple years. Document what you find as best as you can. Doing so will help to preserve the memory of these forgotten roadways for many years to come.
Realigned sometime in the 1930’s, the original alignment of US 99 is still visible near the intersection of Valley Blvd and Pepper Ave. Little remains of the original paving of US 99 through the Los Angeles area, so this is a special section.
Looking west along the original paving.
Original paving, looking east.
Cross section of the original paving. Note the lack of rebar. This is most likely from the 1910’s.
Around late 2007, Valley Blvd was again realigned to better accommodate traffic at the I-10 interchange. Sections of the 1930’s paving are now sticking out from under the asphalt.
Colton welcome sign and old Valley Blvd.
Concrete from the 1930’s visible under the asphalt cover.
On Tuesday, May 13, 2014, I took the opportunity to ride up to Burbank and get some videos of the North Burbank UP with my GoPro camera. Despite the extreme heat, I managed to at least get some good video. These videos show the North Burbank Underpass and ancillary structures from all directions. They were taken to show what they were like before the closure and removal.
Northbound along San Fernando Blvd
Southbound along San Fernando Blvd
Southbound from San Fernando Blvd to Victory Place (Future San Fernando Blvd)
Northbound Victory Place to San Fernando Blvd
Southbound from I-5 at Buena Vista St to San Fernando Blvd
