California Highways: 
Click here for a key to the symbols used. An explanation of acronyms may be found at the bottom of the page.
Routing
From Route 580 in Oakland to Route 680 in Walnut Creek.
Post 1964 Signage HistoryIn 1963, there was an additional segment before this one: "Route 17 near Castro Street in Oakland to Route 580". In 1981, Chapter 292 deleted this segment, moving that routing to I-980. That segment was originally LRN 226, defined in 1959.
This segment (former (b), now (a)) remains as defined in 1963.
In 1966, construction was completed on Route 24 (Grove-Shafter Freeway)
between 0.4 mi W of Route 13 in Oakland and the Caldecott Tunnel in
Berkeley (1.3 mi).
(Source: CHPW Nov/Dec 1966)
The Gateway Boulevard viaduct on Route 24 west of Orinda may have been
constructed for the intersection of a future freeway, according to one
account that I read. I have not yet confirmed this. The viaduct is located
near where Route 93 was planned to intersect Route 24.
(Source: Mail from Jason A. Bezis, 7/2/2002)
Pre 1964 Signage History In 1931, a routing from a proposed Oakland tunnel to Walnut Creek was proposed. This appears to correspond to the eventual Route 24,
however, this segment was not included in the original signage of Route 24
defined in 1934. See below for a full discussion of the original Route 24.
California Highways and Public
Works, in April 1931, reported that Joint Highway District Number 13,
composed of Alameda and Contra Costa counties, had organized for
construction of a public highway and tunnel to supersede the pre-1931
narrow, crooked and inadequate 'Tunnel road in Alameda County and to
improve the Contra Costa County road from the tunnel to the town of Walnut
Creek. The state proposed for inclusion as a state highway that portion of
the route in Contra Costa County between. the tunnel and Walnut Creek, a
distance of 9.6 miles. Based on the volume and class of traffic on the
pre-1931 tunnel road and on the other highways leading into Oakland (one
from Livermore via Hayward, the other from Martinez through Crockett), and
estimating the effect of better facilities in the Walnut Creek area, the
conservative 12 hour traffic was anticipated for 1940 as equivalent to a
24 hour traffic of 17K vehicles on Sundays and 10K on weekdays. The state
felt this route qualified for state inclusion based on volume, importance,
and character of 1931 and future traffic.
The routing has been signed as part of Route 4 (LRN 75, defined in 1931) before the Route 24 signage. In October 1935, it was reported that the Route 24 signage had been extended south from Sacramento to Oakland, via Isleton, Antioch, and Walnut Creek. This may have been related to the opening of the Broadway Tunnels. Note that portions of what was Route 24 are present-day Route 242 and Route 4.
The original routing for Route 24 included what is now Route 13 (renumbered in 1964) between the present Route 13/Route 24 interchange in Oakland and I-80. That segment was LRN 206, and ran along Ashby Avenue. It was added to the state highway system in 1935. However, the actual highway did not exist until the Broadway (later called "Caldecott") Tunnel opened in 1937.
The Ashby routing was part of the larger Bay Bridge project which included construction of the Eastshore Highway with which Ashby connected. On the other side of the hills, Route 24 was routed on Mount Diablo Boulevard.
Caldecott Tunnels and Predecessors
The original routing between Oakland and Lafayette over
the Berkeley Hills of Alameda County followed a steep ascent via what is
now Telegraph Avenue and Claremont Avenue. Upon cresting the Berkley
Hills this road would have followed what is now Fish Ranch Road in Contra
Costa County. The first known concept for a tunnel through the
Berkeley Hills emerged in 1860 but was rejected by the populace in Alameda
County and Contra Costa County. Another concept emerged in 1871 as
an extension of Broadway via a vaguely described path which would emerge
somewhere near San Pablo Creek in Contra Costa County. This 1871
concept would eventually emerge as the route of a choice for a tunnel and
would sporadically be under construction during the following
decades. Eventually the tunnel construction was taken up by the
Merchants Exchange of Oakland which procured the funding and permits to
complete construction.
(Source: Gribblenation Blog (Tom Fearer), “Former California State Route 24 through the Kennedy Tunnel and Old Tunnel Road”, January 2021)
The resulting "Inter County Tunnel" was opened November
4th, 1903, and was later renamed as the "Kennedy Tunnel". It was a
single-lane, timber-supported, 1000' structure that served as a conduit
until 1937, when the first Caldecott bores were completed and dedicated.
The tunnel closed in the 1940s. Lafayette residents protested the tunnel,
predicting that it would increase competition for land and price them out
of the market. But private and county money eventually financed a tunnel.
The Kennedy Tunnel had a four-foot elbow in the middle; diggers had
miscalculated the meet-up. The tunnel was also called the the Broadway
Tunnel (although that name was also used for the Caldecott, at one time).
The western entrance was near Tunnel Road and Skyline Boulevard. The
eastern entrance is at the end of Old Tunnel Road. At the east entrance, a
residence owned by the East Bay Regional Park District stands on the
former site of the Canary Cottage cafe. The original tunnel has been
abandoned and the ends sealed.
(Image source: December 1937 CHPW)
Broadway was chosen for LRN 75 (Route 24) over versus
Ashby Avenue (LRN 206 / Route 13) as Broadway, at the time, connected
directly with Tunnel Road whereas Ashby Avenue did not yet connect.
(Source: Gribblenation Blog (Tom Fearer), “Former California State Route 24 through the Kennedy Tunnel and Old Tunnel Road”, January 2021)
In 1937, the Caldecott Tunnels (called the Broadway Low-Level Tunnels) opened, a twin-bore tunnel designed to replace the dark, dank, single-bore Kennedy Tunnel 300 feet above it. At that time, some 30,000 cars were passing through Kennedy every week. The twin tunnels, each 3000' feet, were concrete lined, lighted, and had forced air ventilation. Note that as the two tunnels were curved at the end and joined one another at a single portal building at each end, there was a belief that there was just a single tunnel with a thin concrete supporting wall. In reality, the roadways are 150' apart except at the two ends. Each of the tunnels has a 22' wide roadway and a with of 26' 8" between the sidewalls. Each bore carried one direction of traffic.
Development in Contra Costa boomed and a third bore opened in 1964, outfitted with a system of tubes that popped out of the pavement and allowed workers to change directions of the middle bore to handle traffic, which generally flowed west in the morning and east in the evening. Modern standards required that the highways at each end of the tunnels be widened and straightened and that the third bore be made wider than the first two. As the third tunnel was to be considerably larger than the two older tunnels, it was not possible to adapt the original plans to the new location. The third tunnel has a 28 foot wide roadway and is 34 feet 6 inches wide between the sidewalk. The vertical clearance is 17 feet above the pavement, compared with the 14 feet 10 inches in the two older bores. In addition to the larger size of the tunnel itself, there are numerous other features which are new or improved. The entire length of the roadway is illuminated by a continuous line of fluorescent lights on each side of the ceiling. Extra lights are placed for a distance of 300 feet at each end so that there is a gradual transition in the daytime in order to allow drivers' eyes to adjust to the change from the bright sunlight outside and the artificial light in the center of the tunnel. Emergency power facilities have also been installed for use in the event that there is a power loss from the serving utilities. A new transverse system of ventilation is being used. Fresh air is taken in at the westerly portal building and carried along a duct above the roadway. It is discharged into the roadway section through openings at one side of the ceiling. The fresh air mixes with exhaust fumes from the vehicles, and is drawn out through exhaust ports on the opposite side of the ceiling, then carried to the westerly portal building and discharged straight up into the atmosphere. The two fresh air and two exhaust blowers have a capacity of a half-million cubic feet of air per minute. On October 6, 1964, dignitaries from throughout the area assembled to dedicate Tunnel III to the name and further honor of Thomas E. Caldecott.
Adorning the original Caldecott
Tunnel bores are medallions that were designed by Henry Meyers, the
official Alameda County architect in the 1930s. One depicts people facing
each other to symbolize how the tunnel joins the residents of Contra Costa
and Alameda counties; another shows a car headlight exiting a tunnel.
Meyers may have had a lot of help from draftsman George Klinkhardt in
designing the tunnel exterior and medallions, a Caltrans report suggests.
In fact, Klinkhardt may have designed the entire tunnel exterior, the
reports says. Meyers, who grew up in Livermore and whose Alameda home has
been turned into a museum, designed more than 200 buildings, including
Highland Hospital in Oakland, the Posey Tube in Alameda and 10 veterans
memorial buildings, including the ones in Livermore and Pleasanton. In
2012, Caltrans held a student design competition to design medallions to
adorn the new 4th bore. The competition will be limited to students from
Contra Costa and Alameda counties. The six new hexagon-shaped medallions
-- each about 36 inches high -- will be public art for the ages.
In July 2012, the updated artwork was chosen. Specifically, six students’ winning images of Mount Diablo, rugged foothills, and the sun will be built into the exterior of the Caldecott Tunnel Fourth Bore.
StatusThis route is constructed as a freeway.
The 2022 SHOPP included the following new project: 04-CC-24 R0.01. PPNO
0480B; ProjID 0414000011; EA 0J540. Route 24 In Orinda, at the Caldecott
Tunnel № 28-0015R, 28-0015, and 28-0015L. Rehabilitate Caldecott
Tunnel Bores 1, 2, and 3. Total Project Cost: $69,487K. Begin Con:
10/1/2026.
(Source: “2022 State Highway Operation
And Protection Program, Fiscal Years 2022-23 through 2025-26”,
March 17, 2022)
4th Bore - Caldecott Tunnel (~ ALA R5.858 to CC R0.416)
In September 2000, the California
Transportation Commission considered (TCRP Project #15) a $15 million
allocation for phase one of construction of a fourth bore tunnel with
additional lanes for the Caldecott Tunnel (~ ALA R5.858 to CC R0.416). The
total estimated cost is $185 million. This project was requested by the
Metropolitan Transportation Commission. Bore 3, constructed in the early
1960's (long after bores 1 and 2) was actually constructed with the fourth
bore being kept in mind. As evidenced by the tunnel, stub lanes (on both
ends of the tunnel) do actually indicate a 4th bore was in
mind, as small strips of pavement (wide enough for 2 lanes) spur from the
existing highway before fading off into the bushes and trees before
entering the tunnel. This is currently planned to complete construction in
late 2012. Funding was extended for this in September 2005.
The SAFETEA-LU act, enacted in August 2005 as the reauthorization of TEA-21, provided the following expenditures on or near this route:
In February 2006, the CTC noted that the goal of TCRP Project #15 is to improve the movement of people and goods along Route 24 via the Caldecott Tunnels, to improve travel time and therefore reduce delays, and enhance safety of the traveling public and Department maintenance workers. When the environmental process started, seven alternatives were under consideration. Based on several screening criteria, four alternatives were dropped. The elimination of the four alternatives reduced the cost and the Department and the Contra Costa Transportation Authority (CCTA) have identified $5,000,000 of available TCRP funds for other work. In February 2006, the Department and CCTA request that the funds be redistributed to Plans, Specifications, and Estimates. The Draft Environmental Document is being finalized and will be ready for circulation in July 2006. The alternatives being considered are:
The Final EIR was received in December 2007, and the CTC indicated construction is estimated to begin in Fiscal Year 2009-10. The total estimated project cost, capital and support, is $420,000,000. The project is funded from $175,000,000 local funds, $20,000,000 Traffic Congestion Relief Program funds, $1,000,000 Federal Demonstration funds, $18,000,000 in Regional Improvement Program funds, $31,000,000 Interregional Improvement Program funds, and $175,000,000 Corridor Mobility Improvement Account funds. The funding sources were adjusted in June 2008.
In January 2009, Caltrans removed one of the last obstacles preventing it from adding a fourth bore to the Caldecott Tunnel by settling a lawsuit with Oakland residents concerned about the impacts of building the new tunnel. The settlement to the suit by the Caldecott Fourth Bore Coalition calls for Caltrans to:
The settlement was crafted between attorneys for the coalition and Caltrans with pressure from state legislative leaders and Gov. Arnold Schwarzenegger, who wanted to see the fourth bore built as part of his state economic stimulus strategy. He had sought to have the project exempted from the environmental review process, which would have nullified the suit, but that undoubtedly entangled the project in other legal challenges. However, the project may still get caught up in the 2008/2009 Budget mess. The $420 million Caldecott Tunnel project depends on $194.5 million from the transportation infrastructure bonds voters approved in 2006. Plans to hire a contractor to start digging the long-awaited fourth bore this summer were halted Jan. 14 2009, when the California Transportation Commission froze funding for the Caldecott Tunnel and 26 other projects that had been scheduled to receive $293.5 million in state funding. If the governor and the Legislature settle the budget crisis by early February, the fourth bore could receive funding from the transportation commission on Feb. 18 and Caltrans could start the process of hiring a contractor by March 1 - just two to four weeks behind schedule.
At the January 2009 meeting, the CTC deferred to February (and in February, deferred it to March... and in March, to April) discussion about reorganization of this project. The intent is to split the original project into four segments, as follows:
The basic plans for the project are:
In April 2009, the CTC approved funding this project (as a loan against future bonds) from 2009 Stimulus funds. It was advertised for construction in May 2009.
In late January 2010, politicians and transportation
officials gathered in an enclosed and heated tent in Orinda, not far from
the tunnel, to celebrate the official groundbreaking for the $420 million
fourth bore. After an hour and a half of speeches, they grabbed
gold-painted shovels and dug from a pile of dirt trucked in for the
ceremony. Actual construction was already under way with contractors
clearing brush and preparing to erect retaining walls on both sides of the
tunnel and a sound wall on the west end. In June 2010, workers expect to
begin digging the new tunnel from both ends. Tunneling crews will dig the
new hole in the Oakland hills in segments, first digging out the top of
the tunnel, then building the tunnel gradually by excavating a segment and
bolstering it with braces and sprayed concrete. They will also dig seven
cross-passages to the third bore - to provide emergency exits. The
completed bore will be 41 feet, 3 inches wide and 3,389 feet long.
Caltrans officials expect the project to create about 5,000 jobs during
the four years of construction. Nearly half of the money to pay for the
project is coming from federal stimulus funds. John Porcari, deputy
secretary of the U.S. Department of Transportation, said the fourth bore
is the largest recipient of stimulus funds for infrastructure in the
nation.
(Source: "Work begins on Caldecott Tunnel's 4th bore", San Francisco Chronicle, 1/23/2010)
Before the actual tunnel construction starts in July
2010, there has been significant preparatory work. Since January 2010,
construction crews have been busy building retaining walls to keep the
hills from collapsing onto Route 24. To build the retaining walls, crews
are boring holes about 2 1/2 feet across, 8 feet apart and 36 feet to 97
feet deep. The bottoms of the holes are filled with concrete, then steel
I-beams are dropped in. When all the beams are in place, the dirt in front
of them will be removed and wooden planks will be inserted between the
beams to hold back the hillside. Eventually they'll be covered in
concrete. The crews are also constructing and portal walls that will form
the eastern and western entrances to the new two-lane fourth bore. Just
north of the existing westbound tunnel, workers are preparing the concrete
and steel faces through which the digging of the fourth bore will
commence. The face is a series of interlocking columns formed by boring
holes, filling them with concrete, then boring new holes in between, and
filling them with concrete. The walls are then tied together and
strengthened with steel, creating a strong surface to dig through. Walls
on each side of the face are built by covering the soil with concrete then
inserting long, thick steel reinforcement rods into the earth. They're
grouted in place and act like long, strong nails. Workers have also
constructed a $3.5 million charcoal gray temporary sound wall between the
freeway and the apartments and condos on Caldecott Lane, just west of the
tunnel. This wall was constructed by putting I-beams in the ground,
putting huge wooden planks between them, then fastening 2-inch-thick
noise-absorbent plastic pads on both sides. The walls sport slanted tops
pointed toward the freeway. The idea is to trap the noise, light and dust
generated during construction when trucks use the narrow strip between the
freeway and the wall as a staging ground with a concrete plant,
water-treatment facility and dumping area for soils excavated from the
Oakland hills. Additionally, trees have been removed from the hillsides, a
traffic signal is being installed on Upper Broadway, and three electrical
substations are under construction.
(Source: "Caldecott Tunnel fourth bore under construction", San Francisco Chronicle, 5/21/2010)
In his 2006 Strategic Growth Plan, Governor Schwartzenegger proposed completing the Caldecott Tunnel Corridor. In 2007, the CTC recommended using $175M from the Corridor Mobility Improvement Account (CMIA) for the 4th bore.
In July 2010, it was reported that The $420 million excavation of a fourth bore of the Caldecott Tunnel between Orinda and Oakland has opened a door for paleontologists to search for fossils expected to give clues to old life-forms and climate change in the Bay Area. Private paleontologists hired by Caltrans already have found a tooth — likely a remnant of a camel — and dozens of remains of fish scales, plants and other bone bits in dirt and rock dug up, shoved around and shored up in early construction work outside the new bore site. One area considered prime for fossil finds is the Orinda Formation, a jumble of fractured layers of old stream beds and flood plains. The silt and sediment there is ideal for covering up and preserving fossils from creatures that roamed the East Bay 9 million to 10 million years ago in the Miocene period. This is the first time that Caltrans has called in paleontologists to a Bay Area freeway project at its beginning to monitor for fossils. Caltrans said it is paying about $35,000 a month for the paleontological work. The duration of the collection will be shaped by how long the crews keep finding fossils.
In March 2011, it was noted that, after a year of construction, construction crews have dug out more than 900 feet -- or 27 percent -- of the 3,389-foot-long Caldecott Tunnel fourth bore, a project now estimated to cost $391 million after favorable construction bids lowered the cost from $420 million. The 21,665 cubic meters of earth and rock excavated from the Caldecott fourth bore so far would cover a football field 16 feet deep. When the project is finished, the excavated earth would cover a football field 134 feet deep.
In September 2011, the New York Times reported on this construction. It noted that the project was projected to create 4,500 jobs. The work in the tunnel is more dangerous than work in the average tunnel. Safety regulators declared it “gassy” from the start because of the naturally occurring methane gas in the guts of the Berkeley Hills. Anything that could spark an explosion, from cellphones to lighters, is banned from the inside of the tunnel. Because of sections of precariously weak rock, miners must use what is called the New Austrian Tunneling Method, meaning that crews dig just short distances before taking measures to reinforce the tunnel. The digging machine, called a roadheader, is a 130-ton instrument that looks like a metal brontosaurus with a spiked metal rotating head for grinding rock. It is followed by a remote-controlled robot on wheels that sprays a special quick-drying concrete over the newly bored section. With another machine, the miners then drive long steel dowels into the tunnel walls to reinforce them before proceeding. Once the boring is completed, it will take two more years to scoop out the bottom portion, install ventilation, lighting and communication systems, and otherwise transform the rough-hewn hole through the hills into a subterranean stretch of freeway. By the end of 2013, the tunnel be able to accommodate four lanes of traffic in each direction. It will eliminate the need for Caltrans workers to engage in an often futile game of trying to minimize backups by switching the direction of traffic through the center bore at least twice daily, often more frequently.
In November 2011, it was reported that construction of the fourth bore broke through the Orinda hillside, thus connecting the two sections of the tunnel being dug. In January 2012, it was reported that state safety regulators have ruled the fourth bore project is no longer classified as a "gassy" tunnel, where methane and other gases could trigger explosions or fires.
In March 2012, it was reported that a competition was being held to design adornments for the 4th bore. Caltrans announced in late March 2012 the opening of the unusual competition to design six, 36-inch tall architectural medallions that will be cast out of concrete above the entrances to the Caldecott Tunnel fourth bore on Route 24. May 7 2012 was the deadline to submit original art deco drawings, which Caltrans plans to use in designing molds for pouring concrete to form the decorative shapes. The competition was limited to students from kindergarten through high school in schools in Contra Costa and Alameda counties. This is the first student-only architectural design competition Caltrans has used in the Bay Area. Caltrans picked "classic art deco" as the theme after the art style was strongly favored in an agency online poll on six different themes, and was the theme used on the other bores.
In April 2012, it was reported that excavation was taking longer than expected, owing to tough digging conditions. In Fall 2011, a crew of miners and their brontosaurus-like digging machine encountered unexpectedly difficult conditions — including harder rock formations and, in some places, water.
In August 2012, it was reported that the 4th bore was
completed. This bore contained safety features developed as a result of
the crash of a drunk driver inside the Caldecott Tunnel on April 7, 1982.
The crash touched off a chain reaction that turned the third bore into a
2,000-degree tomb and killed seven people. There were no emergency
passages, and the narrow tunnel had no shoulder. There were no traffic
lights, emergency gates or message signs to warn motorists of the fireball
inside, caused when a gasoline tanker burst into flames. Utilizing lessons
leared from this accident, new safety features for the third and fourth
bores include traffic lights and a traffic gate that swings down in
emergencies. The third and fourth bores also will be the first to have an
extensive network of electronic message signs and traffic signals inside;
and unlike the original two bores, the third and fourth will be connected
by seven lighted, 12-foot-wide escape passages. The escape passages are
air pressurized to keep smoke and toxic gases away from fleeing travelers.
Additionally, only the fourth bore has a shoulder, a 10-foot wide swath to
stash damaged vehicles or for fire trucks, ambulances or law enforcement
to access accidents. The Caldecott Tunnel also is safer than it was in
1982 because of a ban on trucking gasoline and other flammable liquids or
poison gases through the tunnel, except between 3 and 5 a.m. Even when the
new bore opens, some safety features will be hidden, such as water lines.
Some will be too small to see, like heat sensors. Most obvious will be 19
ceiling-mounted fans, all capable of churning up 20 mph breezes to sweep
away smoke and gases. The fans are more powerful than those in the other
bores. One new safety feature common to all four bores is a radio override
system that allows tunnel operators to broadcast emergency messages on car
radios, regardless of the station to which they are tuned.
(Source: Contra Costa Times, 10/31/13)
In November 16, 2013, the new fourth bore opened.
Naming
Route 24 from Interstate 580 to the
Caldecott Tunnel (~ALA R1.914 to ALA R5.837) is named the "William
Byron Rumford Freeway". Byron Rumford was a State legislator. Named
by Assembly Concurrent Resolution 137, Chapter 92 in 1980. The dedication
plaque reads: William Byron Rumford Freeway, Member of the California
Legislature 1948-1966, Community and Civic Leader. This freeway on the
state system is named in honor of William Byron Rumford Sr. for his long
and dedicated service to his state, community, and mankind." William Byron
Rumford (February 2, 1908 – June 12, 1986) was a pharmacist,
community leader, and politician. He was the first African American
elected to any public office in Northern California, and the first African
American hired at Highland Hospital. Rumford graduated from a segregated
high school in Arizona in 1926. At 18, he moved to San Francisco and
worked for a year, before attending Sacramento Junior College. The School
of Pharmacy at the University of California, San Francisco accepted
Rumford, and he worked his way through school, working as a parking valet
and a doorman at night, and graduated in 1931. While at UCSF Rumford was a
member of the Alpha Phi Alpha fraternity. At the age of 25 William Rumford
passed the State of California employment examination in 1933, at a time
when very few African Americans worked for the State. After passing the
employment exam, Rumford took the California Board of Pharmacy
investigator examination, where he twice passed the written part of the
exam, but was twice failed on the oral portion. Rumford then passed the
examination for California State Venereal Disease investigator, but again
was failed on the oral presentation portion for a third time. Undaunted,
Rumford visited one of the members of the Personnel Board who lived in
Oakland. Christenson, the board member, appealed the Board's decision to
fail Rumford based on the grounds that he was asked irrelevant questions.
Rumford went on to appeal on the grounds that the Board had publicized
statistics that African Americans suffered from sexually transmitted
diseases at a greater rate than other ethnic groups, but had not taken
done anything to improve the situation. Rumford won the appeal and was
granted his California State certification. Rumford became co-owner of a
pharmacy in Berkeley in 1942 at the age of 34, which he later purchased
outright and renamed Rumford's Pharmacy. He tried to continue with his job
at Highland Hospital while running the pharmacy. Eventually, Rumford
decided to leave Highland Hospital, devoting his time fully to the
pharmacy. In addition to his business, Rumford was director of the Red
Cross Oakland chapter, President of the East Bay Health Association, and a
member of the Democratic Central Committee for the Bay Area. In 1944, he
was appointed by Governor Earl Warren to the Rent Control Board. He helped
found the Berkeley Interracial Committee. Rumford served in the California
State Assembly from 1948–1966, with a special focus on in fair
employment, control of air pollution, and fair housing. In 1955, Rumford
first introduced a Fair Housing Act, and in 1963, the California State
Legislature passed the Rumford Fair Housing Act which outlawed restrictive
covenants and the refusal to rent or sell property on the basis of race,
ethnicity, gender, marital status, or physical disability.
(Bio: Oakland Wiki; Image source: Read the Plaque; Join California)
This segment is historically part of "El Camino Sierra" (Road to the Mountains). It continues along what is now I-680.
Named StructuresThe “Kennedy Tunnel”, the predecessor tunnel to the Caldecott or Broadway Tunnel, was named for L. W. Kennedy. Kennedy is said to have first conceived the idea of a toll road and tunnel between the counties. He started a company which built a road and began work on a tunnel, but "Work was begun upon the hole in the hill, but a rush of water was struck to the extent that it collapsed the tunnel and the company at the same time." Note that other sources claim that Wright F. Kelsey was the first to propose building a tunnel between the counties.
The "Caldecott Tunnel" (structure 28-015) (~ ALA R5.858 to CC R0.416) on Route 24 between Alameda and Contra Costa Counties was named
for Thomas Edwin Caldecott (July 27, 1878 – July 23, 1951), who was
a pharmacist and politician when the tunnel was built. From 1923,
Caldecott served in politics in Alameda County, California in the San
Francisco Bay Area until 1951. Caldecott was born in Chester, England on
July 27, 1878. Both of his parents were Welsh. The family immigrated to
Toronto, Ontario, Canada about 1882. Caldecott grew up in Canada, and
obtained a pharmacy degree from the University of Toronto in 1900. Thomas
and his brother visited Berkeley, California, and shortly thereafter in
1903, moved their entire family there. That same year, Caldecott bought a
pharmacy at Dwight Way and Shattuck Avenue, later moved to Ashby Avenue
and Adeline Street in the Webb Block, a building which was designated a
local landmark in 2004. Caldecott was elected to the City Council of
Berkeley in 1923. In 1930, he was appointed to fill out the remaining term
of Mayor Michael B. Driver. He then successfully ran for the office of
Mayor in 1931, serving until December 1932. He was then elected as a
supervisor on the Alameda County Board of Supervisors, serving from 1933
until his death in 1951. He was chairman of the board from 1945-1946. In
1948, he formed the Alameda County Highway Committee, "to solve sectional
differences over highway problems." He was also instrumental in
establishing a new Alameda County Juvenile Hall, which was completed after
his death in 1951. Caldecott served as the president of Joint Highway
District 13, which oversaw the construction of the multi-bore Broadway Low
Level Tunnel through the Berkeley Hills east of San Francisco Bay. When
opened in 1937,[14] it was the longest tunnel in the State of California,
and accomplished the opening up of the entire region east of the hills as
a major suburb of the Bay Area. At an event that year, Caldecott was
honored "as the man responsible for the success of the project". In 1941,
Caldecott was publicly commended for his "untiring efforts" in bringing
the project to a successful completion. In 1960, the tunnel was re-named
the "Caldecott Tunnel", in recognition of his leadership on the project.
The tunnel was originally called the "Broadway Low-level" Tunnel
(the former tunnel through the Oakland hills was at a much higher
elevation.) It was built in 1937 and refurbished in 1965, and was named by
Assembly Concurrent Resolution 8 in 1969.
(Image source: Oakland Museum; Bio information: Wikipedia)
The fourth bore of the Caldecott Tunnel (Route 24,~ CC R0.071) is named the Representative
Ellen O’Kane Tauscher Memorial Bore. It was named in memory
of Ellen O’Kane Tauscher, a dedicated public servant serving
the 10th Congressional District from 1997–2009. Ellen O’Kane
was born in Newark, New Jersey, in November 1951, the daughter of a
grocery store owner. She earned a degree in early childhood education from
Seton Hall University in 1974. In her mid-20s, she became one of the first
women to hold a seat on the New York Stock Exchange, serving from
1977–79, and during her 14-year Wall Street career, she also served
as an officer of the American Stock Exchange. In 1989, Ellen O’Kane
married William Tauscher and raised a daughter, Katherine. The couple
later divorced. In 1992, Ellen O’Kane Tauscher founded a service for
preemployment screening of childcare providers. She later authored the
Child Care Sourcebook. She also created the Tauscher Foundation, which
donated two hundred thousand dollars ($200,000) to California and Texas
schools to buy computer equipment for elementary education. Ellen
O’Kane Tauscher received her first political experience serving as
the state cochair for Dianne Feinstein’s successful 1992 and 1994
Senate campaigns. In 1996, Ellen O’Kane Tauscher challenged
incumbent California Republican Representative William P. Baker in a newly
created Delta district comprising bedroom communities that are the most
conservative in the San Francisco Bay area. She ran on a platform of gun
control, women’s reproductive rights, and increased spending on
education, along with the reduction of wasteful fiscal spending and
narrowly won, with 49 percent of the vote to Baker’s 47 percent, in
a race with three minor party candidates. In the next two elections,
Representative Tauscher won by slightly more comfortable margins over
Republican candidates, defeating Charles Ball 53 percent to 43 percent and
Claude B. Hutchinson 52 percent to 44 percent. When Representative
Tauscher took her seat in the 105th Congress (1997–1999), she was
assigned to three committees: National Security (later renamed Armed
Services); Science, Space, and Technology; and Transportation and
Infrastructure. In the 106th Congress (1999–2001), Representative
Tauscher resigned her Science, Space, and Technology Committee seat to
focus on her two other assignments, where she remained for the balance of
her career in the House of Representatives. Representative
Tauscher’s committee assignments provided her a national platform
from which she also was able to serve district needs. As a member of the
Armed Services Committee, she outlined an activist role for the United
States in the international arena. Her district was the only one having
two national defense laboratories, Lawrence Livermore and Sandia, and she
secured nearly $200,000,000 in funding for Livermore’s “super
laser” project. Representative Tauscher also had a prominent role as
the senior Democrat on the congressional panel overseeing the National
Nuclear Security Administration, which manages the United States nuclear
weapons program. From her seat on the Transportation and Infrastructure
Committee, Representative Tauscher steered federal funding to improve the
San Francisco Bay area’s badly strained transportation systems,
including $33,000,000 for projects in her district. In 1998, Time magazine
dubbed her moderate Democratic approach to politics
“Tauscherism,” a kind of middle-of-the-road politics that
blended fiscal conservatism with social liberalism and reflected the
political realities of her suburban district, which, until reapportionment
in 2002, was more Republican than Democratic. When the lines were redrawn
by the California Legislature, Representative Tauscher easily won
reelection to a fourth term, with 75 percent of the vote against
Libertarian candidate Sonia E. Harden. In 2004, Representative Tauscher
won reelection with 66 percent of the vote against Republican Jeff
Ketelson, and in 2006 and 2008 voters returned her to office with 66
percent and 65 percent of the vote, respectively. On May 5, 2009,
Representative Tauscher was nominated by President Barack Obama to be the
Under Secretary of State for Arms Control and International Security. On
June 25, 2009, Representative Tauscher was confirmed to the position of
Under Secretary of State by a voice vote of the United States Senate and
resigned her seat in Congress the next day to take the position.
Representative Tauscher represented the United States at numerous
international meetings and negotiations, including setting into motion the
New START Treaty, the first major nuclear arms reduction and limitation
agreement with Russia in over two decades, which was signed in 2009, and
ratified in 2010. Representative Tauscher served the Obama administration
as Under Secretary of State until February 7, 2012, when she was named
Special Envoy for Strategic Stability and Missile Defense, a position she
held until August 31, 2012. In 2013, Representative Tauscher was elected
chairperson of the Alliance for Bangladesh Worker Safety, a group of 28
global retailers, and led efforts that created industry safety standards
in response to the fire and collapse of a Bangladeshi garment factory that
killed over 1,000 workers. In March 2013, Governor Edmund G. Brown, Jr.,
appointed Representative Tauscher as the chair of the Governor’s
Military Council and was tasked with expanding defense industry jobs and
investment in California. On September 17, 2013, Representative Tauscher
was named as an independent member of the Board of Governors for Lawrence
Livermore National Laboratory and Los Alamos National Laboratory, and
served as chair of the Board of Governors beginning on February 16, 2018.
On June 2, 2017, Governor Edmund G. Brown, Jr., appointed Representative
Tauscher to serve on the Board of Regents of the University of California.
She passed away in 2019. Named by Senate Concurrent Resolution 77, Res.
Chapter 32, 09/11/20.
(Image source: Find a Grave)
Interstate SubmissionsThe portion from Route 13 to Walnut Creek was submitted for inclusion in the interstate system in 1945; it was not accepted.
Scenic Route[SHC 263.3] From the Alameda-Contra Costa county line to Route 680 in Walnut Creek.
Classified Landcaped FreewayThe following segments are designated as Classified Landscaped Freeway:
| County | Route | Starting PM | Ending PM |
| Alameda | 24 | R1.85 | R4.88 |
| Alameda | 24 | R5.24 | R5.89 |
| Contra Costa | 24 | R0.40 | R0.62 |
| Contra Costa | 24 | R1.82 | R2.85 |
| Contra Costa | 24 | R3.29 | R5.26 |
| Contra Costa | 24 | R5.53 | R9.14 |
From Route 680 in Walnut Creek to Route 4 near Pittsburg.
Post 1964 Signage History
In 1963, this segment was defined as "Route 680
in Walnut Creek to Route 4 near Pittsburg." In 1981, Chapter 292 changed
the wording to "near Walnut Creek", but it was changed back to "in Walnut
Creek" by Chapter 1187 in 1990.
Planning maps have shown a routing that follows Willow Pass road from Walnut Creek to just outside of Antioch. Until 1991, Route 242 between Concord and Route 4 was signed as Route 24, but field reports indicate this is no longer the case. There is one map that shows Route 24 continuing northeast of Route 4 to Collinsville and then towards Route 160
In Concord, the freeway routing was constructed by 1992; that routing was transferred to Route 242. The traversable routing that corresponds to the proposed bypass is Ygnacio Valley Road and Kirker Pass Road. The traversable routing was considered adequate in 1972, but local agencies have discouraged state adoption. The freeway route adoption was rescinded effective 4/16/1975.
The 2013 Traversable Routing report notes that the segment from Route 680
to Route 4 corresponds to Ygnacio Valley Road and Kirker Pass
Road. Considered adequate in 1972, but local agencies have discouraged
state adoption. Freeway route adoption (4.5 miles) was rescinded 4-
16-75. No recommendation.
Pre 1964 Signage HistoryThis new routing is LRN 256, added to the state highway system in 1959. Present-day Route 242 was signed as Route 24 prior to 1992.
StatusIn June 2011, it was reported that the Walnut Creek City Council had a number of plans for Ygnacio Valley Road, including in-pavement lights at various locations, $550,000; Ygnacio Valley Road sidewalk, Oakland Boulevard to Parkside Drive, $750,000; speed display signs along Ygnacio Valley, $130,000; left turn extension lanes at Ygnacio Valley and San Carlos Drive, $500,000; southbound left turn extension lane at Civic Drive and Ygnacio Valley, $600,000; eastbound left turn extension at Ygnacio Valley and Marchbanks Drive, $300,000; westbound left turn extension on Ygnacio Valley at Walnut Boulevard, $400,000; and a westbound left turn extension on Ygnacio Valley at Homestead Avenue, $350,000.
Prior to 1964, Route 24 continued from Pittsburgh to a junction with US 395 near Hallelujah Junction via Oroville and Quincy.
Post 1964 Signage HistoryThe 1964 renumbering reallocation the segments E of Pittsburgh to Route 4 (Concord to Antioch), Route 160 (Antioch to Sacramento), Route 16 (Sacramento to Woodland), Route 113 (Woodland to Yuba City/Marysville), and Route 70.
Pre 1964 Signage History
In 1934, Route 24 was signed along the route from
Woodland at Jct. US 99 to Jct. Route 7 (now US 395) near Reno Junction,
via Oroville and Quincy (Reno Junction was likely the former name of what
is now Hallelujah Junction, Reno Junction having replaced Chats). It
appears it was extended, perhaps in 1936, to eventually have the route
from US 40 in Oakland to US 395 near Reno Junction.
Route 24 started at US 40 (now I-80) at the Oakland City Hall at 14th and
San Pablo. It then ran along Broadway to College, then along College to
Claremont Ave. Along Claremont, it entered Berkeley. It jogged briefly
along Ashby Avenue (present-day Route 13, LRN 206, defined in 1935) to
Tunnel Road, continuing into Contra Costa County. The route was LRN 75.
(Source: Old Oakland Maps, 1936)
Route 24 then ran E to Walnut Creek (along present-day Route 24); this was LRN 75. It was then likely cosigned with Route 21 until the Route 21/Route 24 junction (this segment of Route 21 was also LRN 75). This was all defined in the 1931-1933 time, but was not signed as Route 24 in 1934.
From Route 4 (Route 24's present-day terminus), it continued cosigned with Route 4 between from near Concord to near Antioch (this was LRN 75, defined in 1931).
Route 24 then ran N to Sacramento, following the route of present-day Route 160, entering along Freeport Blvd. This was LRN 11, defined in 1933. It originally ran N on Freeport to Broadway.
In Sacramento, Route 24 ran W along Broadway as part of LRN 50. It
then ran N along 3rd/5th St., also as part of LRN 50 (Route 16, defined in
1933). It continued N to "I" street, co-signed with Route 16.
Prior to 1960, Route 24 continued W out of the city co-signed with Route 16 along LRN 50 to Woodland.
In Woodland, Route 24 diverged from Route 16 and continued N to Yuba City/Marysville along LRN 87. It was cosigned with US 40A, and this segment is now part of Route 113.
In 1954, Sign Route 24 was either co-signed or resigned as Alt US 40
(US 40A). The article announcing the designation indicated that existing
signs would be replaced by US 40 signs with the designation "Alt". The
article indicated that for the first 10 miles N, from US 40 in Solano
County, the new alternate route would be designated as US 99W and US 40A.
A new section of highway was being constructed to intersect with the
existing US 99W at the Woodland Wye. This would be the segment that is now
Route 113. In Woodland, US40A joined with the existing US 99W / Sign Route 24 to Yuba City; this is now Route 113. US 40A then followed Sign Route 24
(now Route 70) through Oroville and Quincy to US 395. Lastly, US 40A
followed US 395 S to Reno, which was the eastern terminus of US 40A. The
goal here was to provide an alternate route across the Sierras when Donner
Pass was closed.
(Source: Roseville Press-Tribune 3/23/1954 via Joel Windmiller
(email), 11/12/2023)
Around 1960 the routing changed to a new routing along LRN 232, which used Jiboom Street and El Centro Street. This routing used the original Jiboom Street bridge over the American River and Main Drainage Canal. The Gribblenation Blog, "Highways in and around Old Sacramento; US 40, US 99W, CA 16, CA 24, CA 70, CA 99, CA 275, and more" provides a detailed history of the various highways (US 40, US 99, Route 16, Route 24, Route 70, Route 99, Route 275, Route 51, I-5, and I-80 in the Old Sac area.
In October 2018, it was reported that the City
of Sacramento and Caltrans have initiated a project that will replace the
historic I-Street Bridge (for vehicular traffic) and the Jibboom Street
approach to the bridge for a new vehicular continuation of Railyards Blvd.
to C Street. The I Street Bridge is 100 years old (and is a former routing
of Route 16, Route 24, US 40, and US 99) and the lanes are too narrow to
serve buses, there are no bicycle lanes, and sidewalks are too narrow to
meet accessibility standards. The I Street Bridge and the four associated
approach structures are on the eligible bridge list for federal funds for
replacement and/or rehabilitation through the Highway Bridge Program
(HBP). The I Street Bridge has been classified as functionally obsolete,
and the existing approach structures have been classified as structurally
deficient. The I Street Bridge Replacement project will include
construction of a new bridge upstream of the existing I Street Bridge. The
new bridge will cross the Sacramento River between the Sacramento
Railyards and the West Sacramento Washington planned developments and
provide a new bicycle, pedestrian, and automobile crossing. The existing I
Street Bridge would continue to be used by the railroad. The approach
viaducts to the existing I Street Bridge will be demolished, which should
result in better access to the water front in both cities. (See Route 16
for the new routing)
(Source: City of Sacramento, I-Street Bridge Replacement)
Over on AAroads, Scott Parker (Sparker) noted the following about the I-Street routing: The original LRN 232 (after 1959 signed as Route 24) diverged from LRN 50/Route 16 at the intersection of the I Street extension bridge immediately east of the Sacramento River swing-span (shared with UP/former SP tracks on the lower/ground level deck) and Jiboom Street (both are elevated over the RR tracks). It headed north on Jiboom over a through-truss bridge crossing the American River; the street ended at Garden Highway -- atop the river levee --, at which point LRN 232/Route 24 turned west. About a mile west of there, the state highway diverged from Garden Highway along a broad arc descending north from the levee onto El Centro Avenue, which it utilized north into Sutter County. LRN 232 and Route 24 terminated at LRN 3/US 99E at a diamond interchange in Olivehurst.
In November 2022, it was reported that the
plan to turn the top level of the I Street Bridge into a pedestrian
walkway and bike lane over the Sacramento River was progressing. In Fall
2022, project planners filed financial documents, and in late October 2022
the project was recommended for a $16 million grant through the
state’s Active Transportation Program. The current bridge will be
superseded by a new bridge between C Street in West Sacramento and the
Railyards — a $260 million, 300-foot-long feat of architecture that
will replace the I Street Bridge as the route cars take over the river. As
for the old bridge, the plan is to use the 111-year-old I Street Bridge
for railroad traffic, which runs on the bottom deck of the bridge. As for
the top? The city of West Sacramento has spearheaded the plan to repair
the bridge’s narrow sidewalk and turn the vehicle lanes into a
bicycle track and walkway. The $16 million state grant still has to be
formally approved by the state Transportation Commission. The Sacramento
Area Council of Governments previously awarded the project $3.6 million to
complete the final design and right-of-way phase. The total cost of
planning and constructing the project is estimated at $22.6 million. After
securing more than $19 million in outside funding, the city will pay the
rest. Final planning should be complete and construction could be ready to
begin in or before 2026 — but that will largely depend on the timing
of the completion of the new Railyards bridge. The plan is to be ready so
that as soon as the new bridge is cleared to start taking vehicle traffic,
the deck conversion of the old bridge can start. The project should be
finished by late 2027 or 2028.
(Source: Sacramento Business News, 11/7/2022)
In 1959, the CHC adopted a routing for a connection between the "future Route 232 (LRN 232) freeway"
(today's Route 70 freeway routing) and the existing Route 232 highways
(Feather River Blvd) near Rio Oso. This connector swings W from the
adopted freeway route to join Feather River Blvd about a mile to the west.
It is hard to see today, because although Feather River Blvd was "new"
Route 24 (and later Route 70) at the time, it has since been relinquished
by the state and downgraded to a county road. The plans called for the
building of a two-lane bridge over the Bear River, upstream from the
existing bridge. This is part of the first stage of construction of the
new Route 70 freeway. The article indicated that when the LRN 232 freeway
(today's Route 70) was extended to US 99E (Route 99) in Marysville, this
connection would be incorporated into the Bear River interchange, and used
as a county road connection (as LRN 232 would move off Feather River
Blvd). However, in 1959, Feather River Blvd was new Route 24 headed north
on El Centro Road from the Sacramento River. Old Route 24 resigned the Alt
US 40 1955-64 alignment (current 113) from Woodland, which headed north at
Tudor at the current junction of Route 99 and Route 113 then headed north
into Yuba City. In this area for a small period of time (i.e., from 1964
until I-5 was completed and US 99 signs came down), California had both US 99 and California Route 99, but not on the same stretch of highway.
(Source: 1959 news clipping via Joel Windmiller, 1/27/2023)
From Marysville, Route 24 ran through Oroville continuing through
to Belden (this was LRN 87 (defined in 1933) between Robbins and Oroville,
and LRN 21 (defined in 1909) to Belden, and is present-day Route 70), and
then E through Twain, Quincy (running concurrant with Route 89) to Mohawk
(this was LRN 21), and then by its lonesome to US 395 near Long Creek
(also LRN 21).
The portion from near Cherokee and Quincy was under construction, and so a Temporary Route 24 ran from Oroville to Quincy through Berry Creek and Merrimac and Bucks (likely a temporary routing of LRN 21, 1934-1935, perhaps today's Route 162). The Feather River routing was used between 1935 and 1953. Later, a portion of Route 24 was redesignated as Alternate US-40 [1953-1964; for a while, cosigned as Route 24/US 40A] (and is present day Route 70), and Route 24 was truncated to the present day route of Route 99 and Route 113 and Woodland (pre-1964 LRN 87). Route 24, cosigned with Route 16, ran from Woodland to Sacramento. Later, that portion was taken from Route 24, becoming part of I-5.
According to Chris Sampang and Joel Windmiller, the following are some former routings of US 40A/Route 24 between Woodland and Reno:
Chris also notes that Scott Road north of Reno Junction to just south of Omira was also US 395 pre-expressway. Constantia Road between Omira and Doyle, Doyle Loop in Doyle itself, and Old Highway from Doyle to just west of Lassen County Route A26 also appear to be former alignment (Old Highway passes south of the Doyle State Wildlife Area, but the current US 395 expressway goes right through it between Laver Crossing and Lassen County Sign Route A26.)
National Trails
This route was selected by the Victory Highway Association as part of its route from Sacramento to
San Francisco by the 1926 opening of the Antioch-Sherman Bridge, in spite
of the twelve miles of poor road S of Rio Vista and the two ferries
existing at Three-Mile Slough and at Antioch-Sherman.
(Source: Email from Joel Windmiller, 2/4/2023; Image source: PBA Galleries)
StatisticsOverall statistics for Route 24:
Exit Information
Other WWW Links
Freeway[SHC 253.1] Entire route. Only (1) is constructed to freeway standards.
Pre-1964 Legislative RouteThe route that was to become LRN 24 was initially defined in the 1909 First Bond Act as running "From [LRN 4] near Lodi to San Andreas". It was affected by the 1911 definition of the "Alpine State Highway" (Chapter 468), which was defined as:
"The certain road commencing at the Calaveras big tree grove located in Calaveras County thence running to Dorrington in said county, thence E-ly following what is known as the Big Tree and Carson Valley Turnpike to Mt. Bullion in Alpine Cty, thence along county road to Markleeville in Alpine Cty, thence along that certain road via Kirkwood, Silver Lake, Pine Grove and Irishtown to Jackson in Amador Cty, including therewith the road from Picketts in Hope Valley connecting with the Lake Tahoe Wagon Road, a state highway, at Osgood's Place in El Dorado Cty, and the road from Mt Bullion via Loupe in Alpine Cty to Junction in Mono County connecting with the Sonora and Mono State Highway is hereby declared and established a state highway and shall be designated and known as "Alpine State Highway""
For LRN 24, this added the segment between Calavas Big Trees and Route 89.
It was further extended in 1924 from Route 49 near Angels Camp to Calaveras Big Trees, by Chapter 375, which stated “That certain county road in Calaveras County commencing at a point where such highway connects with the Mother Lode State Highway at Angels Camp, extending through Vallecita and Murphy and connecting with the Alpine State Highway at Calaveras Big Trees in the national forest is hereby declared to be a state highway...” Legislation in 1933 extended it further, adding a segment from "[LRN 23] near Woodfords to the California-Nevada state line". Thus, by 1935 when the route was codified, the definition was:
In 1957, Chapter 36 deleted the reference to Vallecita. Signage on the route was as follows:
This segment was signed as Route 12 from US 99 (LRN 4) to San Andreas, where it joined Route 49 (LRN 65).
This segment started at Route 49 (LRN 65). It was signed as Route 4, and ran to Route 89 (LRN 23) near Markleeville.
This segment began at the Route 89/US 395 junction to the Nevada state line. It was co-signed as Route 4/Route 88.
© 1996-2020 Daniel P. Faigin.
Maintained by: Daniel P. Faigin
<webmaster@cahighways.org>.
Route 23
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