Interstate 15 approaches the Marine Corps Air Station at Miramar north of California 52 in the springtime. It is hard to believe that this area burned in the October 2003 Cedar Fire. Photo taken 02/16/05.
Interstate 15 is a major route from the Southwest into the Intermountain West, connecting San Diego and Los Angeles to Las Vegas, St. George, Provo, Salt Lake City, Pocatello, Idaho Falls, Butte, and Great Falls. Interstate 15 replaced Former U.S. 91 almost in its entirety, although a short stretch of U.S. 91 remains in eastern Idaho and northern Utah.
The following list provides a brief history of Interstate 15 in the San Diego metropolitan area:
Mid-1950s. U.S. 395 is rural highway for its entire San Diego County length except for Cabrillo Freeway section in Balboa Park. Plans call for the entire route to be upgraded to freeway standards. This includes the Escondido Freeway from Miramar north to Escondido.
1957. First time that an extension of Interstate 15 south from near San Bernardino to San Diego is suggested, with the rationale that such a highway could connect military bases in San Diego with Air Force bases in Riverside and San Bernardino Counties. It is not incorporated in original Interstate Highway System.
1967. Escondido Freeway complete as far north as Rancho Bernardo Road. California 103 is commissioned along current Interstate 15 south of Miramar Road via Murphy Canyon Road, Ward Road, 40th Street, and Wabash Boulevard.
December 1968. Interstate 15 extension south to San Diego finally added to the Interstate Highway System after intense lobbying from San Diego and other Southern California politicians who would stand to benefit from such a freeway. This original plan has Interstate 15 culminating at the 32nd Street Naval Station (southwest of Interstate 5).
1971. Interstate 15/Escondido Freeway complete as far north as Lake Hodges. California 103/future Interstate 15 freeway construction through Murphy Canyon ongoing.
1975. Emergence of California 15 south of Interstate 8 along Ward Road, 40th Street, and Wabash Boulevard. California 15 replaced California 103 between 1971 and 1975.
1994. Unit One of California 15/40th Street Freeway Project ($7,000,000) completed.
1995. Upgrade of California 15/California 94/Home Avenue Interchange ($12,000,000) completed.
1996. Unit Two of California 15/40th Street Freeway Project ($71,000,000) started.
1998-1999. Incremental new stretches of the Interstate 15/40th Street corridor open to traffic. Planned opening of complete freeway scheduled for Summer 2000. Work begins on interchange realignment and reconstruction along California 15 near Market Street and Ocean View; this work is necessary to bring the old Wabash Boulevard freeway to Interstate standards.
January 14, 2000. The northbound lanes of the 40th Street Freeway, signed as California 15, is completed and opened to traffic. Plans call for both northbound and southbound traffic to use the northbound lanes, with two lanes in each direction separated by jersey barrier, until the summer. However, the full freeway does not open until six months after the stated summer goal.
Summer 2000. Traffic on Interstate 15 north of California 163 approaches new heights in average vehicles per day. Congestion is standard on the freeway during rush hours, even in the section supported by the dedicated high occupancy vehicle lanes. More car pool lanes, along with additional regular lanes, are considered by Caltrans and SANDAG while trying to improve travel times along this corridor.
December 5, 2000. In the 40th Street Corridor, the full freeway has still not opened. The four new southbound lanes were opened in early December between Adams Avenue and Landis Street, but two lanes on the northbound side of the freeway will be closed for completing work on the median. Now Caltrans projects opening the full freeway in January 2001. Signage still refers to the freeway south of Interstate 8 as "California 15."
December 2001. The full freeway is finally opened, culminating years of planning and construction dating back to when Interstate 15 was added to the Interstate Highway System 1968. The 40th Street Freeway is still signed as "California 15," but this is attributed to ongoing construction at the California 94 interchange and Imperial Avenue area that will bring the older freeway section to current Interstate standards.
August 2003. With much anticipation, the express lanes of Interstate 15 between California 163 and California 56 are opened on weekends for a pilot program. Northbound lanes will be opened first for a set amount of time during the day, followed by southbound lanes several weeks later. After the initial testing, by September the lanes will be open in one direction for the entire weekend. The extension of the lanes to Escondido is expected to be complete by 2007. Construction is well underway between California 56 and Escondido by Spring 2004.
Planned Improvements
Interstate 15 has experienced the most traffic growth of any freeway in San Diego County. Fast-paced growth and a North San Diego County housing boom have fueled traffic counts along this highway, causing many to reconsider purchasing a home along the Interstate 15 corridor. In 1988, Interstate 15 saw only about 196,000 cars per day. Today, that count has risen to 281,000 cars per day, with the busiest section located between California 163 and Miramar Way. By 2020, analysts estimate that Interstate 15 will carry upwards of 330,000 vehicles, a 17% increase.
Short-term solutions to this problem include adding more "auxiliary" lanes to Interstate 15. In some cases, this includes restriping shoulders and narrowing lane widths to accommodate more freeway lanes. The auxiliary lanes would enhance traffic flow between freeway entrances and exits. Restriping would allow more lanes to fit in a narrow area, such as the Lake Hodges bridge.
Some planners pitched the idea of creating a "zipper" system for Interstate 15. Under this plan, the freeway would be widened for southbound traffic in the morning and for northbound traffic in the evening. The three to four center lanes would be adjusted to accommodate traffic flow with a special truck that can move jersey median barriers. Enhancements in these trucks may increase speed and efficiency so that the entire operation could take less than an hour.
Currently, more traffic travels in one direction during rush hours. However, some regional planners suggest that Interstate 15 may someday have a more even traffic flow in both directions during rush hours. This may render the zipper system idea ineffective.
Another option is to extend the Interstate 15 express carpool lanes north from California 56 to California 78 in Escondido. The carpool lanes could potentially be operated as a toll facility similar to the manner in which California Transportation Ventures (CTV) operates the existing Interstate 15 express lanes.
In September 1998, reporters from the San Diego Union-Tribune drove Interstate 15 for five days in a row between one mile south of Deer Springs Road (north of Escondido) south to California 52. Under regular, free-flowing traffic conditions, this trip should take about 23 minutes. However, during the morning commute just after 7:00 am, the trip took one hour, 10 minutes on Thursday, September 3rd. Much of the slowing along Interstate 15 occurs near Miramar/Pomerado Road, Carroll Canyon Road, Carmel Mountain Road, and Camino Del Norte.
Much of this traffic is due to new housing developments and the lack of major surface arterials that carry north-south traffic. Already, another 12,800 houses are planned in the Interstate 15 corridor, including Black Mountain Ranch (5,400), Torrey Highlands Ranch (2,693), and Pacific Highlands Ranch (4,974). Black Mountain Ranch made the news during the Fall 1998 campaign. Two local propositions, K and M, were approved by the electorate. These propositions opened parts of the City of San Diego's future urbanizing areas for development. One of the tenets of this agreement included Black Mountain Ranch paying for highway improvements, including along Interstate 15 and California 56. In Spring 2001, a new development known as Rancho Encantada with its hundreds of homes is again on the forefront of the discussion of the impact of new housing against the existing highway infrastructure.
The need to improve Interstate 15 through this corridor has not gone unnoticed at the state level. In Governor Gray Davis' traffic relief plan, released May 3, 2001, $5.5 million was allocated to the high-tech managed lanes concept along Interstate 15 between California 163 and California 78. This initial money will likely be used for a study to plan out the managed lanes concept. The total project cost is estimated to be around $535 million (May 2001), depending upon how many lanes and transit stations for buses are constructed and whether Interstate 15 will need to be widened. It seems likely that the freeway will be widened, especially if a dual freeway or freeway-within-a-freeway (using the zipper system of moving the center concrete barrier) is constructed. The high-tech component would be sensors embedded in the concrete to make adjustments to the roadway to facilitate traffic flow. This will all be considered with the design study.
Currently, Interstate 15 ends at the Interstate 8/Interstate 15 junction near Qualcomm (Jack Murphy) Stadium. South of that point, the Interstate 15 freeway becomes California 15, which becomes the city arterial 40th Street. For these few miles between Interstate 8 and Interstate 805, California 15 is not constructed to freeway standard. South of Interstate 805, California 15 is freeway but not yet Interstate standard -- Caltrans is in the process of reconfiguring the California 94 (Martin Luther King Jr. Freeway, Market Street, and Imperial Avenue) interchanges and lane alignment. Just south of this area, California 15 ends just south of the Interstate 5 interchange at 32nd Street and Harbor Drive, in the community of Barrio Logan in San Diego.
Construction of the 40th Street corridor to Interstate standards was underway between 1996 (groundbreaking) and 2000. In 1997, the excavation of the freeway between El Cajon Boulevard (Business Loop I-8) and Interstate 805 began. Support pillars for the future cut and cover, one-block tunnel were erected, and grading began to create an easier grade up the hill from Interstate 8 to El Cajon Boulevard. The objective of the project, according to Caltrans District 11 Director Gary Gallegos, is to ensure that "the image is one of motorists driving along El Cajon Boulevard, passing business after business, and with the exception of seeing the on and off ramps, never knowing they crossed a freeway." On January 14, 2000, the freeway's northbound lanes opened to both southbound and northbound traffic. By Summer 2000, the complete eight-lane freeway was complete and open to traffic.
Facts about the California 15 Freeway Construction Project, which is anticipated to be completed by the summer of 2000 (from Gallegos' "Building An Invisible Freeway: Caltrans works with the community to lessen freeway impacts," San Diego Metropolitan Magazine, August 1999):
Freeway is 25 feet below the existing ground level.
Widened bridges over the freeway will be able to hold several two-story lightweight buildings, with cobblestone features, decorative railings, and street lamps.
Extra-wide sidewalks and sound walls.
Many formerly busy streets, including 40th Street itself, will become cul-de-sacs, eliminating all but local residential traffic.
Three community parks, including one on top of the freeway, will be built or improved.
Four landscape projects will begin along the freeway even before the final pieces of the construction project are completed.
Almost 1.9 million cubic yards of dirt will be moved -- enough to completely fill Qualcomm Stadium three times -- and more than 10 million pounds of steel used to reinforce 120,000 cubic yards of concrete.
Nearly 12 miles pipe for water, sewer and storm drain facilities all within the 2.2-mile construction area had to be replaced.
Two pedestrian bridges will be constructed: one at Monroe Avenue, leading to a new community park, and the other at Landis Street giving access to the YMCA.
New bus pads will be constructed at the El Cajon Boulevard and University Avenue interchanges. The pads are a separate lane exclusively for buses at the top of each off ramp that will allow them to exit the freeway, allow passengers on and off the bus, then immediately get back on the freeway.
According to Gallegos, "About 40,000 vehicles per day used California 15, also known as 40th Street, before construction began. Compare that number with the 210,000 motorists per day who use the congested Interstate 805 just a few miles away, many of whom will switch to this new section of Interstate 15 when it is completed. This project will help improve traffic flow around the region on Interstate 805, Interstate 8, California 94 as well as in the immediate neighborhood.
Officially, California 15 will remain signed and referred to as a "State Route" until the Interstate-compatible freeway along 40th Street is completed and upgrades to the freeway south of Interstate 805 are completed. At that time, that segment will be evaluated for inclusion into the Interstate highway system. California 15 will become Interstate 15 for several reasons:
Original 1968 plans called for Interstate 15 to continue south to the 32nd Street Naval Station in San Diego/Barrio Logan. This is still the plan, pending upgrading the freeway to Interstate standards.
The white Caltrans Project Description Signs and contractor shields along the 40th Street corridor show Interstate 15 shields rather than California 15 shields. This does not mean anything (since Caltrans has erroneously posted Interstate shields for California 152 and 242).
Several San Diego Union-Tribune newspaper articles indicate that the 40th Street corridor will become an Interstate highway rather than remain a state route.
California 15 is included in the National Highway System, while some other local California freeways are not.
California 15 between Interstate 5 and Interstate 8 was added as a "non-chargeable" (139b) Interstate highway in 1984 (see his page for details on chargeable versus non-chargeable Interstate highways).
Gary Gallegos, the former Caltrans District 11 Director, has referred to California 15 as Interstate 15, even in the quote above.
When completed, the 40th Street corridor of California 15 (Future Interstate 15) became the most expensive freeway (per mile) in San Diego County. Of course, this without considering other potentially expensive projects in the region, such as California 125. The 40th Street Corridor Project has been on the books since around 1957. The story of the City Heights neighborhood had the missing link of Interstate 15 cutting through the heart of that community.
Once the Interstate 15/California 94 interchange is revised between 2005-2010 (contingent upon funding availability), the California 15 freeway may be signed as Interstate 15.
Signage for Junction California 15 as found along Market Street in Southeastern San Diego. Photos taken 06/22/99.
Views of the freeway entrance signage along Former California 274 (Balboa Avenue) onto Interstate 15. Photos taken 11/00.
Scenes pertaining to Interstate 15 - San Diego County
Los Penasquitos Bridge
Interstate 15 crosses over Los Penasquitos Canyon over a tall, wide bridge. It replaced a much older, two-lane arch bridge that carried traffic over the same canyon when this route was U.S. 395. These pictures show the much larger Interstate 15 bridge alongside the original U.S. 395 bridge. This style of arch bridge construction was very common in early Caltrans highway development in the 1920s through 1940s. Today, old U.S. 395 acts as a service road and bikepath, and it served as a construction staging area when the Interstate 15 bridge was retrofitted for earthquakes. This bridge is located just south of the Poway Road/Rancho Penasquitos (San Diego County Route S-5) exit off Interstate 15. Each of these pictures were taken alongside the freeway bridge and on top of or alongside the old U.S. 395 bridge. As seen from the underside of the Interstate 15 bridge, it has been expanded several times to accommodate the center reversible high-occupancy vehicle lanes and auxiliary lanes on the mainline since it was originally constructed. This bridge gained an unfortunate notoriety when motorist Cara Knott was murdered by a highway patrolman. As such, this bridge is named in her memory. Photos taken 06/22/02.
Lilac Road Overcrossing
Side and top view of the Lilac Road bridge, which spans Interstate 15 just north of the Old U.S. 395 interchange. Photos taken 06/22/02.
Scenes Pertaining to Interstate 15 - San Bernardino County
Interstate 10 and Interstate 15 trailblazer shields in Ontario. Photo taken by Jeff Royston, 2001.
Southbound ramp from Baker onto Interstate 15 southbound. Photo taken 01/21/02.
Southbound Interstate 15 mileage sign on the onramp from Baker. Photo taken 01/21/02.
Trailblazer shields for southbound Interstate 15 in Baker. Photos taken 01/21/02 and 11/11/00.
