I-4 begins at a semi-directional T interchange with the upper deck of Interstate 5. The Olympic Freeway, as it's called in Los Santos, borders the Downtown and South Los Santos areas. It is completely elevated with four lanes on each side and the Los Santos Transit Arrow line and Strawberry Station running along the freeway's median.
Once it leaves the downtown area, It crosses Route 17 at a "scissor-loop" interchange before flying over the Four Level Interchange-inspired intersection of Route 20 and Interstate 2 one thousand feet later. At this interchange, the route loses two lanes in each direction, and becomes co-signed with Route 15. From this point, it becomes the Palomino Freeway, a rural highway that bisects the Tataviam Mountains and Palomino Highlands. Interstate 4 ends at a two-stack semi-directional T interchange with Sustancia Road.
Although the Interstate system connects all of Los Santos, it is not possible to drive directly on Interstate 4 to Los Santos International Airport. To get there, the player must intersect with Interstate 5 in Little Seoul, then drive approximately 1400 ft and exit to Route 22 and immediately exit to Route 19.
The speed limit on Interstate 4 is 60 mp/h or 100 km/h.
|Strawberry||1A||Elgin Avenue - Downtown , South Los Santos|
|La Mesa||1B||Popular Street - South Los Santos, Vinewood/|
|Murrieta Heights||1C||/ , begins concurrency with|
|Palomino Highlands||1||Sustancia Road - Palomino Highlands, S. A. State Office|
|Tataviam Mountains||Sandy Shoresends and road continues as north -|
|Tataviam Mountains||begins with concurrency with|
|Palomino Highlands||Sustancia Road - Palomino Highlands, S. A. State Office|
|Murrieta Heights||2||/ , concurrency ends with|
|La Mesa||1D||Popular Street - South Los Santos, Vinewood/|
|Strawberry||1C||Elgin Avenue - Downtown , South Los Santos|
|Strawberry||1B||Los Santos International Airport, Vinewood, Rockford Hills-|
|Little Seoul||1A||Innocence Boulevard - Downtown, Little Seoul|
- Interstate 4/Olympic Freeway is based on Interstate 105 in California as it features a Los Santos Metro line running down the middle of the freeway much as the real 105 features the Green Line of the LACMTA running in the median of the freeway. Interstate 4 is also influenced by Interstate 105 as it features a large intersection with Interstate 5 (Interstate 110 in real life), and it runs through central Los Santos on the edge of Downtown and the cities of Strawberry and Davis.
- Interstate 4's real life inspiration ends directly at Los Angeles International Airport although Interstate 4 in game does not terminate at LSIA at all. Interstate 5 serves at the connector for Interstate 4 and the airport through Dutch London Street (Route 22) and its adjacent intersection with Davis Avenue.
- The freeway section between Elgin Avenue and Route 17 exit resembling a penis, another example of Rockstar's sexual humor.
- The real life Interstate 4 exists as a highway in Florida.