Interprovincial 3C

Interprovincial 3C (abbreviated I-3C and officially known as the Cajalco–Ramona Expressway) is a major west–east Interprovincial Highway serving the western region of the Inland Empire. It is an auxiliary route of I-3 and is about 51 miles (82 km) in length. It runs from K.S. Routes 71 and 91 near in  to K.S. Route 60 in. The route exists as a for much of its length. The highway provides congestive relief for the busier 91, 60, and 15 freeways and services several Inland Empire communities in the, Cajalco, , and. Its path links Southeastern Riverside County with the provinces of Orange and the Gold Coast.

Historically, several local and arterial roads existed along the route's current path. The highway was added to the Interprovincial Highway System in 1989 to meet the region's growing population and traffic congestion problems. Initially, the section between the I-3 and Harley John Road received a two-lane expansion in 2004, before other sections received similar renovations. These sections were eventually upgraded to highways by 2010, and the entire route was designated as I-3C. Plans for continued lane expansion, road improvement, and road extensions have been scheduled, pending legislation in Parliament and the Inland Empire Provincial Legislature.

Exit list
SA 0.00–11.4
 * +Interprovincial 3C
 * rowspan=8| Santiago
 * rowspan=8| Santiago
 * rowspan=8|
 * style = "background-color:#DCDCDC;" | 0.00
 * style="background-color:#FFDDDD;" | -
 * style="background-color:#FFDDDD;" | Route 71 (Inland Empire).svg KS 71 –, , and
 * style="background-color:#FFDDDD;" | Eastbound entrance and westbound exit; western terminus
 * style = "background-color:#DCDCDC;" | SA1.47
 * 35
 * Starco Drive
 * style = "background-color:#DCDCDC;" | SA3.04
 * 36
 * Quartz Avenue
 * style = "background-color:#DCDCDC;" | SA4.19
 * 37
 * West Foothill Parkway
 * Signed as 37A (eastbound) and 37B (westbound)
 * style = "background-color:#DCDCDC;" | SA6.16
 * 38
 * Savage Avenue
 * style = "background-color:#DCDCDC;" | SA7.16
 * 39
 * Shady Ridge Boulevard
 * style="background-color:#DCDCDC;" | SA8.92
 * 40
 * Interprovincial 3.svg Interprovincial 3 (San Antonio Freeway) –, , ,
 * I-3 north exit 40A; I-3 south exit 40B
 * style="background-color:#DCDCDC;" |
 * style="background-color:#FFFF99;" | –
 * style="background-color:#FFFF99;" | Interprovincial 3.svg I-3 south (San Antonio Freeway)
 * style="background-color:#FFFF99;" | access only; eastbound exit and westbound entrance
 * rowspan=16| Riverside RV0.00–39.30
 * rowspan=2| Corona Crossings
 * style="background-color:#DCDCDC;" | RV0.50
 * 41
 * Temescal Canyon Road
 * style="background-color:#DCDCDC;" | RV3.09
 * 42
 * Gin Mine Drive
 * rowspan=4|
 * style="background-color:#DCDCDC;" | RV3.61
 * 43
 * La Sierra Avenue
 * rowspan=16| Riverside RV0.00–39.30
 * rowspan=2| Corona Crossings
 * style="background-color:#DCDCDC;" | RV0.50
 * 41
 * Temescal Canyon Road
 * style="background-color:#DCDCDC;" | RV3.09
 * 42
 * Gin Mine Drive
 * rowspan=4|
 * style="background-color:#DCDCDC;" | RV3.61
 * 43
 * La Sierra Avenue
 * rowspan=4|
 * style="background-color:#DCDCDC;" | RV3.61
 * 43
 * La Sierra Avenue


 * }