Interstate 805
, officially designated the Jacob Dekema Freeway, is a north–south auxiliary Interstate Highway spanning 28 miles in San Diego County, California, functioning as a key bypass for Interstate 5.[1] It originates at a junction with I-5 in San Ysidro near the United States–Mexico border and extends northward through Chula Vista, National City, and central San Diego neighborhoods including North Park and Clairemont, before terminating at another interchange with I-5 in the Sorrento Valley area north of La Jolla.[1][2] The route intersects several state highways, such as SR 54, SR 94, and SR 163, facilitating access to urban centers, industrial zones, and the San Diego International Airport vicinity, while carrying heavy commuter traffic that has made it one of the region's busiest freeways.[2][3] Planning for I-805 commenced in 1956 as part of broader freeway development in Southern California, with official designation in 1959 and construction phases from the late 1960s culminating in full completion by 1975.[1][4] In 1982, the freeway was renamed in honor of Jacob Dekema, a longtime California Division of Highways engineer who oversaw much of the state's early Interstate construction.[1] Ongoing expansions, including managed lanes and connector improvements, address persistent congestion and safety concerns on this vital corridor.[5][6]Route Description
Overview and Path
Interstate 805 (I-805) is a north–south auxiliary Interstate Highway in San Diego County, California, functioning as an eastern bypass of Interstate 5 (I-5) through the central portion of the Greater San Diego area.[1] The freeway spans 28.02 miles from its southern terminus at a partial cloverleaf interchange with I-5 in San Ysidro, adjacent to the Mexico–United States border, to its northern terminus at a turbine interchange with I-5 in the Sorrento Valley community of San Diego.[2][1] From San Ysidro, I-805 proceeds northward, initially paralleling I-5 eastward before diverging into urban zones of Chula Vista and National City.[1] It then enters the city of San Diego proper, traversing densely developed neighborhoods including Lincoln Park, Valencia Park, and Mid-City East, while intersecting east–west corridors such as State Route 54 near the southern extent and Interstate 8 farther north.[1] The route continues through semi-rural and suburban landscapes in areas like Tierrasanta and Clairemont, crossing varied terrain that includes valleys and low hills characteristic of the region's inland geography.[2] As a bypass, I-805 offers an inland alternative to the coastal-aligned I-5, facilitating north–south travel while avoiding heavier port and beachfront congestion, and it connects to additional radials like State Route 52 in the Mission Valley vicinity before merging back with I-5 amid growing suburban development in northern San Diego.[2][1] The highway maintains a predominantly straight north–south alignment, with alignments adjusted to navigate urban expansion and natural contours without significant elevation changes beyond typical freeway grading.[1]Major Interchanges and Features
Interstate 805's southern terminus features a major interchange with Interstate 5 in the San Ysidro area of San Diego, facilitating the divergence of inland traffic from the coastal corridor near the Mexico border.[7] This junction supports heavy freight and commuter flows by branching northward as an alternative route.[7] Key intermediate interchanges include the connection with State Route 54 near Bonita, providing east-west access to National City and Chula Vista, and the junction with State Route 125, a toll road extending toward the Otay Mesa border crossing.[1] The most prominent is the symmetrical stack interchange with Interstate 8 in Mission Valley, known as the Jack Schrade Interchange, which includes the elevated Mission Valley Viaduct carrying I-805 over I-8, the San Diego River, and surrounding terrain.[1] Named for former State Senator Jack Schrade, this structure exemplifies complex freeway connectivity in urban San Diego.[1] At the northern end, I-805 rejoins I-5 in Sorrento Valley via another significant interchange, merging high-volume traffic back into the primary north-south artery.[7] Throughout its length, the freeway maintains 8 to 10 lanes to accommodate substantial daily volumes, including trucks serving border commerce.[8] Notable features include the Sweetwater River Bridge between Bonita and National City, which underwent safety enhancements and sound wall installation as part of corridor improvements to address seismic and structural concerns.[9] By paralleling I-5 inland, I-805 alleviates congestion on the coastal route, particularly for cross-border trade avoiding urban coastal bottlenecks.[7]History
Planning and Designation
Planning for Interstate 805 originated in 1956 amid post-World War II population growth and increasing vehicular traffic in the San Diego region, which strained existing roadways like U.S. Route 101 (later Interstate 5).[1] The proposed route aimed to provide a parallel north-south corridor through central San Diego County, bypassing congested urban sections of I-5 to facilitate commerce, military logistics, and commuter travel in an area experiencing rapid suburban expansion.[10] This planning aligned with the broader Interstate Highway System authorized by the Federal-Aid Highway Act of 1956, which allocated 90% federal funding for qualifying routes meeting design standards for interregional travel.[11] The route received federal designation as an Interstate auxiliary in 1958, reflecting its role as a spur and bypass to I-5 while connecting key southern entry points near the U.S.-Mexico border to northern suburbs.[11] California's Division of Highways, the predecessor to Caltrans, coordinated with the federal Bureau of Public Roads to refine alignment studies, incorporating topographic surveys and traffic projections that justified the freeway's 11-mile length from San Ysidro to Sorrento Valley.[1] Funding approvals followed federal criteria emphasizing high-volume corridors, with initial commitments secured in the late 1950s to prioritize construction amid national Interstate goals.[10] At the state level, the California Legislature formally established Route 805 in 1963 via Chapter 385 of the Statutes, defining its path from the international border area northward to integrate with I-5, ahead of the 1964 statewide highway renumbering that solidified its Interstate status.[1] This designation underscored the route's necessity for decongesting I-5's bottlenecks, particularly in industrial and residential zones of National City, Chula Vista, and San Diego proper, where daily traffic volumes were projected to double by the 1970s due to economic development and naval base activities.[11] Caltrans-led environmental and engineering reviews in the early 1960s confirmed the bypass's viability, paving the way for subsequent phases without altering the core alignment established in federal-state agreements.[10]Construction Phases
Construction of Interstate 805 began in 1966 with a 3.6-mile segment from 0.2 miles north of Home Avenue northward to its junction with Interstate 5 near Sorrento Valley, establishing the initial northern portion of the route amid San Diego's expanding suburban development.[1] This phase involved earthwork, bridge construction, and paving to create an eight-lane divided freeway capable of handling projected regional traffic growth, requiring coordination with local land use patterns to integrate the alignment through residential and industrial zones.[1] [12] A formal groundbreaking ceremony occurred on September 25, 1967, at El Cajon Boulevard and Boundary Street, signaling the expansion of efforts southward from the initial segment.[1] [4] Construction proceeded in sequential phases, prioritizing northern extensions before southern segments to facilitate incremental traffic relief and minimize prolonged disruptions in densely populated areas like Clairemont and Serra Mesa.[1] [10] By March 1972, a seven-mile section of the eight-lane freeway had been completed and dedicated, connecting key mid-route interchanges and easing congestion on parallel arterials.[12] Later phases addressed the southern alignment toward San Ysidro, incorporating elevated structures over rail lines and urban corridors to overcome topographic and right-of-way constraints.[1] The full 11-mile route was completed in 1975, marking the end of segmented builds that spanned nearly a decade and aligned with federal Interstate funding deadlines.[1]Opening and Initial Operations
The central seven-mile segment of Interstate 805 opened to vehicular traffic on March 20, 1972, marked by a formal dedication and ribbon-cutting ceremony that highlighted its role as an eight-lane inland bypass to alleviate congestion on Interstate 5.[13] This initial expanse traversed key areas including Mission Valley, connecting northern and southern corridors while integrating with existing interchanges such as those near El Cajon Boulevard and Interstate 8.[14] The opening preceded full route completion in 1975, but immediately supported regional mobility by diverting traffic from urban centers amid San Diego's expanding suburban development.[1] Prior to the public debut, highway officials hosted a Community Cycle Day on March 19, 1972, inviting bicyclists to traverse the fresh pavement over seven miles, an event that generated local enthusiasm and demonstrated the infrastructure's readiness without reported construction defects or delays.[15] Early operations reflected standard freeway protocols of the era, with no documented immediate adjustments beyond routine signage and ramp activations to ensure seamless merging into the broader network linking Sorrento Valley southward.[1] The segment's initial capacity, designed for high-volume flow, catered to San Diego's post-1960s population surge—reaching approximately 1.1 million residents by 1972—by providing efficient north-south linkage for commuters and freight, though specific inaugural traffic counts remain unarchived in available records.[16] In 1982, the full Interstate 805 was officially designated the Jacob Dekema Freeway, honoring the Caltrans District 11 engineer who directed its planning and construction phases.[17]Expansions and Major Projects
In the late 1990s and early 2000s, the I-5/I-805/SR-56 reconstruction project widened existing sections of I-5 and I-805 by two lanes in each direction northbound and southbound, while constructing new freeway bypasses approximately one mile south of the I-5/I-805 interchange to SR-56.[18] This effort enhanced capacity in the Sorrento Valley area to accommodate growing regional traffic demands.[18] A 2007 Environmental Impact Statement evaluated proposals for managed lanes on I-805 South, including construction of high-occupancy vehicle (HOV) lanes, direct access ramps, in-line transit stations, and auxiliary lanes between Palomar Street and SR-15 to improve throughput and transit integration.[19] Building on this, the I-805 South Managed Lanes Conversion Project in the 2010s shifted 8.5 miles of existing HOV lanes to high-occupancy toll (HOT) lanes from Palomar Street to SR-94, enabling dynamic tolling for single-occupant vehicles to optimize flow and fund operations.[5] Similarly, safety upgrades to the Sweetwater River Bridge, completed in 2021, widened shoulders and lanes while adding upgraded signage and barriers between Bonita Road and SR-54.[20] Recent initiatives include the I-805 Middle Pavement Rehabilitation and Asset Management Project, which began in November 2024 and targets nine miles from SR-15 to north of SR-52 with $107 million in funding for grinding, lane replacement, drainage upgrades, and traffic management enhancements, set for completion by fall 2026.[21] The I-805 South Pavement Rehabilitation project, slated to start in November 2025, will address 14.5 miles from the international border to SR-15 at a cost of $222.5 million, focusing on full-depth pavement replacement and infrastructure modernization through spring 2030.[22] Additionally, the I-805 Governor Drive Auxiliary Lane and Bridge Improvement Project, ongoing since February 2024, adds lanes and upgrades structures for better peak-period operations, with completion expected in summer 2025.[23]Design and Infrastructure
Engineering Specifications
Interstate 805 is engineered as a divided freeway with Portland cement concrete (PCC) pavement, constructed to Interstate Highway System standards for accommodating high-speed, high-volume traffic flows. The roadway primarily features six general-purpose lanes—three in each direction—with shoulders and auxiliary lanes added at interchanges for improved merging and safety. Design speeds align with California Department of Transportation (Caltrans) guidelines for urban interstates, supporting posted limits up to 65-70 mph where geometry permits, emphasizing horizontal and vertical alignments that minimize curvature and grades for structural efficiency and vehicle stability.[24][22] Bridges and overcrossings along I-805 incorporate reinforced concrete designs, such as continuous box beam structures, to span waterways and valleys while addressing seismic hazards prevalent in Southern California. The southbound span over the Sweetwater River, a flood-prone area, utilizes concrete continuous box beam construction elevated to mitigate inundation risks during high-flow events, with recent widenings increasing lane and shoulder widths for enhanced load-bearing capacity. Seismic engineering follows Caltrans criteria, including ductile detailing and isolation bearings in retrofitted and new structures to absorb earthquake forces, ensuring post-event functionality without collapse. Interchange designs, such as the high-occupancy vehicle (HOV) direct ramps and flyovers, employ precast concrete segments and steel girders where needed, optimized for traffic weaving reduction and structural redundancy.[25][26][20] Post-2010 infrastructure upgrades include the addition of HOV lanes in the median, converted to high-occupancy toll (HOT) express lanes with variable pricing systems. These lanes feature dedicated pavement sections separated by concrete barriers, equipped with electronic toll gantries using overhead sensors and transponders for dynamic toll collection based on real-time congestion levels. Widening projects incorporated high-strength concrete mixes and geogrid reinforcements for embankments, maintaining pavement integrity under increased axle loads from tolled operations.[27][5][28]Architectural and Artistic Elements
Interstate 805, designated as the Jacob Dekema Freeway, incorporates commemorative elements honoring its namesake, a key figure in California's highway development as former district engineer for Caltrans District 11. A bronze plaque dedicated to Dekema was installed along the freeway at the Governor Drive overpass, recognizing his 42 years of service in advancing the state's infrastructure.[29][30] This plaque, erected in the early 1980s following the 1981 naming, serves as a fixed artistic tribute integrated into the roadside environment, visible to northbound traffic near the Park & Ride lot. Architectural design in key interchanges emphasizes elevated structures and symmetrical layouts to enhance visibility while minimizing visual intrusion on surrounding urban and valley landscapes. The Jack Schrade Interchange with Interstate 8 features a four-level stack configuration, including the towering Mission Valley Viaduct constructed in 1972, which employs reinforced concrete spans to provide unobstructed passage over the San Diego River and rail lines, balancing structural elevation with aesthetic proportionality.[31] Recent corridor enhancements, such as the I-805 South Pavement Rehabilitation project completed in phases through 2023, incorporate compatible architectural details on retaining walls and sound barriers aligned with established South I-805 aesthetic themes, including textured finishes to reduce monotony and integrate with local surroundings.[32] These elements prioritize functional form that softens the freeway's presence amid residential and natural areas, though specific public art installations remain limited compared to other regional highways.Operations and Traffic
Traffic Volume and Congestion
Interstate 805 experiences high traffic volumes, with average daily traffic (ADT) ranging from 160,000 to 261,000 vehicles across its length, reflecting its role as a primary north-south corridor connecting South Bay communities to central and northern San Diego.[33] This volume positions I-805 among the region's most heavily utilized freeways, driven by commuter flows from residential areas in Chula Vista and National City toward employment centers in Sorrento Valley and beyond.[6] The highway's proximity to the U.S.-Mexico border indirectly contributes to these patterns, as cross-border economic activity in the South Bay amplifies morning northward demand.[33] Congestion on I-805 is predominantly directional, with northbound backups peaking during morning rush hours (typically 6:00-9:00 a.m.) due to inbound commuters, often extending from the southern terminus near Palm Avenue to interchanges like State Route 54 and Interstate 5.[34] Southbound flows face delays in the afternoon and early evening, though less severe than northbound peaks, as return trips disperse more evenly; daily congestion durations average 2-4 hours.[33] Bottlenecks frequently occur at merges with Interstate 5 and near the Interstate 15 junction, where volumes concentrate without adequate capacity relief.[35] To mitigate these issues, segments of I-805 feature managed express lanes, including high-occupancy toll (HOT) facilities that employ dynamic pricing to maintain minimum speeds and prevent spillover delays into general-purpose lanes.[5] These market-based mechanisms incentivize carpooling and off-peak travel, reducing overall backups by optimizing throughput during peaks; for instance, conversion projects funded in 2025 aim to expand such lanes southward, enhancing flow reliability.[36] Empirical observations from similar implementations indicate that priced lanes preserve capacity for high-value trips while easing adjacent congestion through demand shifting.[37]Safety and Incident Data
Caltrans data from the Statewide Integrated Traffic Records System (SWITRS) and the Fatality Analysis Reporting System (FARS) indicate that fatal crashes on Interstate 805 predominantly occur in dense urban segments and at interchanges, such as the junction with Interstate 163 and State Route 52. [38] [11] These incidents often involve multiple vehicles, reflecting the challenges of merging and weaving in high-volume areas. [11] The fatal crash rate for I-805 stands at 0.005 per 100 million vehicle miles traveled, which is lower than comparable San Diego County routes like State Route 54 (0.010) and State Route 125 (0.009). [39] Overall crash rates, as reported in Caltrans annual summaries, align with urban freeway averages, with interchanges identified as elevated-risk zones due to acceleration and deceleration maneuvers. [40] Property damage-only and injury crashes constitute the majority, but per-mile metrics underscore the route's relative safety when adjusted for exposure. [41] Safety enhancements through infrastructure projects have targeted these vulnerabilities. The I-805 South Bridge Safety and Sound Walls Project added auxiliary lanes northbound from East Naples Street to Telegraph Canyon Road, extending merge distances to decrease rear-end collisions. [26] Similarly, the conversion to managed lanes includes pavement rehabilitation and drainage upgrades, projected to improve operational safety by smoothing traffic flow and reducing conflict points. [5] Post-implementation evaluations of analogous lane additions on California freeways demonstrate reductions in rear-end incidents by up to 20-30%, validating the causal role of expanded capacity in hazard mitigation. [40] The engineered features of I-805, including grade-separated interchanges and barriers, empirically lower collision severity compared to at-grade arterials, as evidenced by Caltrans comparative rate groups showing freeways with fewer severe outcomes per million vehicle miles despite higher absolute volumes. [42] Ongoing monitoring via SWITRS confirms that these design elements, combined with interventions, sustain below-average risk profiles for urban bypass routes. [41]Impact and Significance
Economic Benefits and Connectivity
Interstate 805 functions as a key bypass route parallel to Interstate 5, enabling more direct north-south travel through San Diego County and avoiding congestion in the downtown area. This connectivity links southern communities near the U.S.-Mexico border, including San Ysidro, to northern employment hubs and the broader regional network, supporting daily commutes and freight distribution.[2][43] The corridor enhances economic activity by facilitating the movement of goods and services along a primary transportation artery, particularly vital for San Diego's logistics sector tied to cross-border trade. As part of the South Bay to Sorrento multimodal network, I-805 aids in transforming regional goods movement, reducing bottlenecks for trucks accessing industrial areas and distribution centers. Its role bolsters the Port of San Diego's operations, which generated $13.8 billion in economic impact and sustained 71,000 jobs in fiscal year 2023 through maritime commerce.[44][45][46] Managed lanes projects on I-805, including high-occupancy toll (HOT) lanes funded by a $39.6 million grant in 2025, introduce dynamic congestion pricing to increase throughput and reliability without relying on tax-funded physical expansions. These lanes prioritize high-occupancy vehicles while allowing solo drivers to pay tolls, mirroring successful models on nearby corridors like I-15 that have improved travel reliability for commercial users. By optimizing vehicle flow, such implementations directly contribute to logistics efficiency, minimizing delays that could otherwise hinder just-in-time supply chains and regional productivity.[36][5][47]Environmental and Social Effects
The construction of Interstate 805 during the 1960s and 1970s displaced a significant portion of San Ysidro's population, with reports indicating that one in six residents faced relocation due to land acquisition and demolition for the freeway alignment.[48] Expansions intersecting with Interstate 5 further divided the San Ysidro community, demolishing hundreds of homes and severing neighborhood connections in this border-adjacent area predominantly inhabited by Latino families at the time.[49] Similar disruptions affected other San Diego neighborhoods, including historically Black and Latino enclaves, where freeway routing led to fragmentation of social fabrics and loss of local amenities without contemporaneous mitigation for pedestrian access or community cohesion.[50] Operationally, I-805's traffic volume contributes to localized air pollution, with proximity to the freeway linked to elevated particulate matter and nitrogen oxide levels that correlate with higher incidences of respiratory and cardiovascular health issues in adjacent residential zones.[51] Vehicle emissions along the corridor, particularly from heavy freight use in the South Bay, exacerbate ground-level ozone formation, though regional monitoring shows per-capita reductions in tailpipe pollutants since the 1990s due to cleaner vehicle standards and fuel efficiency gains. Infrastructure upgrades, such as auxiliary lanes added via the Governor Drive project completed in phases through 2025, demonstrably lower net emissions by reducing stop-and-go idling compared to diversion onto more congested alternatives like I-5, with modeling indicating decreased delay-related fuel consumption.[23] Mitigation measures in recent rehabilitation efforts, including the I-805 South Pavement Rehabilitation project spanning San Diego to National City, incorporate stormwater drainage culverts and permeable surfaces to minimize runoff pollution into nearby waterways and habitats.[52] Noise barriers and vegetated buffers have been integrated into asset management upgrades along northern segments, attenuating acoustic impacts on surrounding urban areas while preserving coastal sage scrub remnants through targeted restoration.[53] Socially, while initial construction exacerbated isolation in underserved South Bay locales by prioritizing vehicular throughput over local linkages, the corridor's completion facilitated broader regional access for low-income commuters to northern job centers, offsetting some prior inequities through reduced travel barriers absent equivalent rail options.[54] Ongoing state initiatives, such as Caltrans' Reconnecting Communities pilot, fund caps or retrofits at I-805 interchanges to restore pedestrian and bike connectivity in divided neighborhoods like National City, addressing lingering disparate access without evidence of unmitigated long-term economic exclusion when accounting for usage patterns across demographics.[55]Criticisms and Debates
The proposed expansions of Interstate 805 in the 2000s, including managed lanes, prompted preparation of an Environmental Impact Statement to evaluate potential effects on urban development patterns and emissions, amid public concerns that added capacity could encourage peripheral growth and vehicle dependency. Opponents, including local advocacy groups, contended that such projects inadequately addressed induced demand leading to sustained congestion and localized air quality degradation, challenging the adequacy of mitigation measures in the environmental review process. Supporters, including transportation officials, emphasized that converting existing lanes minimized new land use impacts compared to full widenings, aligning with regional mobility needs driven by population increases from 1.3 million in San Diego County in 2000 to over 3.3 million by 2020.[19] Construction of I-805 during the 1960s and 1970s involved eminent domain acquisitions that bisected established neighborhoods in areas like Southeastern San Diego and Encanto, altering community fabrics and prompting displacement complaints similar to those in contemporaneous national highway revolts. Critics at the time highlighted disproportionate effects on lower-income and minority residents, with the route's path through diverse urban zones raising equity issues in land valuation and relocation support. Defenders pointed to the highway's role in establishing a vital north-south bypass, enabling freight and commuter access that underpinned subsequent economic expansion, including job growth in South Bay industries exceeding 100,000 positions by the 1980s.[56] Debates surrounding the conversion of high-occupancy vehicle lanes to high-occupancy toll lanes on I-805, funded in 2025, center on accessibility, with detractors labeling dynamic pricing as inherently regressive by pricing out solo drivers from modest backgrounds amid median household incomes around $70,000 in corridor-adjacent South Bay communities. Proponents rebut that the voluntary system incentivizes ridesharing—exempt from tolls—and channels proceeds toward infrastructure preservation and transit enhancements, fostering broader throughput gains without mandatory tax hikes. Environmental advocates have endorsed the I-805 approach specifically for avoiding pavement expansion, contrasting it with broader widening initiatives they oppose for amplifying emissions.[36][5]Exit List
Northbound Exits
Interstate 805 northbound features 28 numbered exits from its southern terminus at Interstate 5 in San Ysidro to its northern terminus at Interstate 5 in Sorrento Valley, with exit numbers corresponding approximately to state mileposts as per California's uniform exit numbering system.[57] These exits provide access to local streets, state routes, and connecting interstates serving the communities of San Ysidro, Chula Vista, National City, San Diego, and La Jolla.| Exit | Destinations | Notes |
|---|---|---|
| 1A | San Ysidro Boulevard east | Access to San Ysidro community and historic U.S. Route 101 alignment.[2] |
| 1B | San Ysidro Boulevard west, Dairy Mart Road, CA 905 west | Serves San Ysidro and Otay Mesa areas; partial cloverleaf interchange with CA 905.[58] |
| 2 | Palm Avenue | Local access in San Ysidro.[58] |
| 3 | Main Street, Auto Park Drive | Serves Chula Vista commercial districts.[59] |
| 4 | Olympic Parkway, East Orange Avenue | Access to Chula Vista residential and business areas.[59] |
| 5 | H Street | Connects to National City; also serves as link to County Route S17.[59] |
| 6 | 47th Street | Local access in National City. |
| 7 | 24th Street | Industrial and residential access in National City. |
| 8 | SR 54 east – Point Loma, El Cajon | Diamond interchange providing bypass to downtown San Diego.[58] |
| 9 | Sweetwater Road | Serves National City and South Bay communities.[58] |
| 11 | Market Street | Access to San Diego's Logan Heights neighborhood. |
| 12A | Logan Avenue | Eastern San Diego access. |
| 12B | Imperial Avenue | Connects to local businesses and residential areas. |
| 13A | 43rd Street | Local street access. |
| 13B | SR 15 south – Downtown San Diego | Signed as exit to SR 15 south; no northbound access from this exit.[60] |
| 14 | University Avenue, SR 15 north | Serves City Heights and North Park; SR 15 north to I-8.[60] |
| 15 | El Cajon Boulevard | Access to Mid-City San Diego. |
| 16 | 6th Avenue | Local access near Adams Avenue. |
| 17A | I-8 east – El Cajon, Beaches | Cloverleaf interchange; I-8 exit 6A.[57] |
| 17B | I-8 west – Beaches, Downtown | I-8 exit 6B; milepost approximately 17.5.[57] |
| 18 | Murray Ridge Road, Phyllis Place | Milepost 17.65; serves Serra Mesa area.[57] |
| 20A | Kearny Villa Road, Mesa College Drive | Access to Mesa College and Kearny Mesa; milepost 18.89.[57] |
| 20B | SR 163 south – Downtown San Diego | Cabrillo Freeway connection. |
| 21 | Balboa Avenue | Serves Clairemont neighborhood. |
| 22 | Clairemont Mesa Boulevard | Major east-west arterial in Clairemont. |
| 23 | Genesee Avenue | Access to University City and UTC area. |
| 25 | SR 52 east – La Jolla, Scripps Ranch | Connection to I-5 via SR 52. |
| 27 | Mira Mesa Boulevard, Sorrento Valley Road | Serves Mira Mesa and Sorrento Valley tech corridor. |
| 28 | Carmel Country Road | Local access near northern terminus. |
| 29 | I-5 north – Del Mar, Oceanside | Northern terminus wye interchange at milepost 25.48.[57] |
Southbound Exits
Southbound Interstate 805 travels approximately 28 miles from its northern junction with Interstate 5 in Sorrento Valley to its southern terminus at Interstate 5 near San Ysidro, serving San Diego's northern and central neighborhoods including Mira Mesa, Clairemont, and National City. Exits are encountered in descending numerical order from the north, with numbering and mileposts standardized by the California Department of Transportation based on distance from the southern end.[57] The following table lists southbound exits sequentially, including mileposts and destinations:| mi | Exit | Destinations | Notes |
|---|---|---|---|
| 28.73 | 28 | Mira Mesa Boulevard / Sorrento Valley Road | |
| 27.15 | 27A | Mira Mesa Boulevard / Vista Sorrento Parkway | |
| 27.07 | 27B | Sorrento Valley Road | |
| 25.94 | 25B | Miramar Road / La Jolla Village Drive | |
| 25.79 | 25A | Nobel Drive | Partial installation; proposed numbering correction |
| 24.44 | 24 | Governor Drive | |
| 23.65 | 23 | SR 52 | |
| 22.56 | 22 | Clairemont Mesa Boulevard | |
| 21.65 | 21 | Balboa Avenue | |
| 20.60 | 20B | SR 163 / Escondido | |
| 20.23 | 20A | Kearny Villa Road / Mesa College Drive | |
| 18.89 | 18 | Murray Ridge Road / Phyllis Place | |
| 17.65 | 17B | I-8 / Beaches / El Centro | |
| 16.99 | 17A | Adams Avenue / Madison Avenue | |
| 16.43 | 16 | El Cajon Boulevard | |
| 15.95 | 15 | University Avenue | |
| 14.64 | 14 | SR 15 North / 40th Street | |
| 13.95 | 13B | Home Avenue | |
| 13.51 | 13A | SR 94 East / MLK Jr Freeway | |
| 12.95 | 12B | Market Street | |
| 12.34 | 12A | Imperial Avenue | |
| 11.31 | 11B | 47th Street | |
| 11.16 | 11A | Palm Avenue | |
| 10.28 | 10 | Plaza Boulevard | |
| 9.05 | 9 | Sweetwater Road | |
| 8.85 | 8 | SR 54 | |
| 7.76 | 7C | Bonita Road / E Street | |
| 7.16 | 7B | H Street West | |
| 7.16 | 7A | H Street East | |
| 6.06 | 6 | Telegraph Canyon Road / L Street | |
| 5.06 | 5 | E Palomar Street | Left exit |
| 4.42 | 4 | E Orange Avenue / Olympic Parkway | |
| 3.65 | 3 | Main Street / Auto Park Drive | |
| 2.90 | 2 | Palm Avenue | |
| 1.81 | 1C | SR 905 | |
| 0.65 | 1B | San Ysidro Boulevard | |
| 0.15 | 1A | Camino de la Plaza |