I-3C highlighted in red
Maintained by IEDOT|
Defined by Interprovincial Highway System Charter § 1211
|Length:||49.61 mi (79.84 km)|
|Existed:||2010 – present|
|History:||1955 as highway; 1989 as number; 2010 as Interprovincial|
|West end:||KS 71/KS 91 in Corona|
I-3 in Corona|
I-3A in Perris
|East end:||KS 60 in Beaumont|
|Auxiliary Routes of I-3|
It is an auxiliary route of I-3 and is about 50 miles (80 km) in length. I-3C runs from K.S. Routes 71 and 91 near Prado Dam in Corona to K.S. Route 60 in Beaumont. The route exists as a limited-access highway for much of its length. The highway provides congestive relief for the busier 91, 60, and I-3 freeways and services several Inland Empire communities in the Temescal Mountains, Cajalco, Mead, and Perris Valleys. 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 an Interprovincial and numbered 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. In 2019, Inland Empire voters approved government bonds of over $30 billion to finance road expansion and improvement projects that would include Interprovincial 3C.
The route is used as an alternative to K.S. 91, K.S. 60, and I-1 for travelers driving between Coachella Valley and the Greater Porciúncula Area. Its official name, the Cajalco–Ramona Expressway, is named after two of its major segments in the Cajalco Valley and Perris–San Jacinto area. At its western terminus, Interprovincial 3C begins at the Green River Interchange between the southern terminus of K.S. 71 and K.S. 91. Between this interchange and the junction at I-3, the freeway has five lanes (one of which is a HOV lane). The locally assigned name to this segment is the Corona Hills Freeway. The road follows the northern slopes of the Santa Ana Mountains along the southern edge of Corona and neighboring unincorporated communities. It includes a fully divided median with sound barriers on both sides. Although the I-3C is numbered as an auxiliary spur route of the I-3, it is technically a spur of the I-1 from its eastern terminus.
I-3C's interchange with its parent route, I-3 is all within Santiago County and Corona, but is less than a quarter of mile from the Santiago–Riverside county line and the unincorporated community of Corona Crossings. At the county line, the lanes are reduced to two lanes, with no HOV lane, and the fourth lane ending at Temescal Canyon Road. This segment, locally assigned the Cajalco Expressway, is downgraded to an expressway as it does not have the features of an Interprovincial standards-compliant freeway. The route ascends the rugged, steep slopes of the Temescal Mountains, which includes several winding curves known by locals as the "Cliffs of Death". The section between Temescal Canyon Road and La Sierra Avenue has been regarded as the most dangerous part of the route and has seen the most fatalities and car accidents due to speeding and low visibility at night. The posted speed limit at this section is 55 mph, which is strictly enforced by radar and aircraft.
After ascending to an elevation of about 1,390 feet, the road's grade becomes relatively flat and travels along the southern shoreline of Lake Mathews. It passes by the unincorporated community of Lake Mathews, a satellite, rural community of Riverside and Corona. Starting at La Sierra Avenue, there is no raised median between both sides of the route. Until 2006, some of the exits were standard at-grade intersections, which had traffic lights. After minor realignments and upgrades, the streets had overpasses outfitted above the route. Just before the El Sobrante Boulevard/Gavilan Road exit, the expressway becomes a freeway again, with a raised median and three lanes. The route passes by the community of Surrey Creek and Mead Valley.
Near the Mead Valley–Perris line and the interchange with I-3A, the road is expanded to four lanes, and is assigned the name Ramona Freeway. It then travels through the northern suburban area of Perris, Lake Perris, and Mystic Lake, before it makes a sharp northward turn at the North Sanderson Avenue / North Ramona Boulevard exit. This section is also the beginning of the I-3–K.S. 79 concurrency route. The route is reduced to three lanes after passing Heritage Drive Avenue as it travels towards Beaumont. The freeway ends just before the interchange with the I-1 and K.S. 60 merging fork, downgrading to a street as Beaumont Avenue. The route number I-3C drops officially just before East 6th Street where Beaumont Avenue continues on while signed as K.S. 79 north alone.
The original route was a series of disjointed road segments which linked rural communities and farms together all throughout the counties of Santiago and Riverside. Citrus farming was one of the region's most lucrative and profitable industries and were delivered to nearby railroads along "farm-to-market" roads. In general, these roads followed artificially paths originally set by ranchers, who brought their herds to local stockyards or stations.
Settlement and development of the Inland Empire picked up during the early 1920s as the province advertised its fertile soil and warm climate as a suitable location for sub-tropical fruits and produce. One of the main complaints newcomers had was the apparent lack of adequate transportation. Large stretches of uninhabited land separated the communities apart and most farm-to-market roads had uneven dirt surfaces and in some cases, even covered or obstructed by overgrown vegetation, debris, and sediment. Travel by vehicle was impractical during the 1920s and this major inconvenience concerned Inland Empire lawmakers. With the exception of the Sierran Numbered Highways and some streets in the more densely populated areas, the Inland Empire lacked well-maintained roads.
The roads that followed the present-day I-3C were formally commissioned under the Road Development, Safety, and Maintenance Act in 1924 which provided over $12 million (in 2016 KSD dollars) to build rudimentary connections between the province's most important communities, namely Riverside, San Bernardino, and Corona at the time. Perfunctory construction began in 1925, and faced bureaucratic backlogs as lawmakers disputed the project's finances. The ensuing Recession of 1929–1931 further delayed any substantial road improvement in the region well into the 1930s, which remained only partially paved at select segments.
During Great War I, production stimulated the national and local economy, and there was a new demand for better transportation to support the Inland Empire's rising importance to Sierra's industrial output. Major construction efforts commenced during and after the war, with Cajalco Road being one of the many such roads paved for use. Traffic along the I-3C's path remained low-intensity until the late 1980s as the Inland Empire experienced a real estate boom and rapidly expanding economy. Thousands of residents from the neighboring Gold Coast and Orange began moving to the Inland Empire for cheaper housing, pressing the need for an even stronger network of roads to support the demographic influx. Major improvements were made to the K.S. 91, K.S. 60, and I-1 freeways, as well as other local roads. The improvements made towards capacity were unable to outpace the growing number of cars on the road. Traffic jams became a frequent, common issue for Inland Empire residents, which was especially pronounced along the K.S. 91 route near the Orange–Inland Empire line in Corona, notoriously known as the "Corona Crawl".
Numerous proposals were made to address the traffic congestion issues. Among those proposals included adding express lanes to K.S. 91 or boring a tunnel through the Santa Ana Mountains as an alternate route. In 2002, Inland Empire Assemblyman Jorge Morales introduced a plan that would convert Foothills Parkway, Cajalco Road, and Ramona Road into highway-level roads.
In 2011, the County of Riverside hired an independent contractor to evaluate and assess the possibility of adding more lanes on the stretch of freeway between the Riverside–Santiago county line and Lake Perris, which would bring the total of lanes for both directions to 6, and allow for a commuter rail service line on the meridian as well. The proposal was met with opposition by environmentalists and locals who believed adding more lanes would be environmentally unsound and bring more traffic to the area.
Note: Except where prefixed with a letter, postmiles were measured on the road as it was in 1964, and do not necessarily reflect current mileage. The numbers reset at county lines; the start and end postmiles in each county are given in the county column.
|Corona||SA0.00||KS 71 (Chino Hills Freeway) – Chino Hills, Chino, and Pomone / KS 91 (Riverside Freeway) – Riverside, Orange, Beach Cities||Eastbound entrance and westbound exit; western terminus ends at southern entrance of K.S. 71|
|SA0.25||91 Plus Express Lanes (QuikTrak required)||West end of 91 Plus Express lanes|
|SA4.19||2||West Foothill Parkway||Signed as 37A (eastbound) and 37B (westbound)|
|SA7.16||5||Shady Ridge Boulevard|
|SA8.92||6||Interprovincial 3 (San Antonio Freeway) – San Antonio, Temecula Valley, San Diego, Las Vegas||I-3 north exit 40A; I-3 south exit 40B|
|–||I-3 south (San Antonio Freeway)||HOV / Express Lanes access only; eastbound exit and westbound entrance|
|91 Plus Express Lanes (QuikTrak required)||East end of 91 Plus Express Lanes|
|Corona Crossings||RV0.50||7||Temescal Canyon Road||Cajalco end of freeway eastbound (becomes expressway)|
|RV3.09||8||Gin Mine Drive||Closed due to environmental reasons|
|Lake Mathews||RV3.61||9||La Sierra Avenue – Riverside, Lake Hills, Victoria Grove|
|RV6.80||11B||Lake Mathews Drive||Westbound entrance and exit via Bullion Road|
|RV9.62||12||El Sobrante Boulevard / Gavilan Road – Woodcrest, Surrey Creek||Signed as 12A eastbound, signed as 12B westbound; Cajalco westbound end of freeway (becomes expressway)|
|Surrey Creek / Mead Valley||RV11.76||12C||Wood Road – Orangecrest||No eastbound entrance; eastbound exit via Fire Ridge Street|
|RV14.26||15||Clark Street / Old Elsinore Road||Former KS 179|
|RV16.22||16||Harmon View Boulevard|
|Perris||RV16.53||17||I-3A (Butterfield Valley Freeway) – Butterfield Valley, Menifeeville, Riverside, San Bernardino||I-3A north exit 17B; I-3A south exit 17A|
|RV17.7||18||Indian Trail Road|
|RV18.95||19||Morgan Street – Lake Perris Provincial Recreational Area|
|RV21.03||20||Sierra Vista Parkway|
|Mystic Lake||RV25.04||22||Hansen Boulevard / Davis Street|
|RV27.89||23||Black Hills Road|
|San Jacinto||RV30.25||24||Warren Road||Signed as 24A (north) and 24B (south) eastbound|
|RV31.72||25||North Sanderson Avenue / North Ramona Boulevard / K.S. 79 south – San Jacinto, Mayberry||South end of K.S. 79 overlap; K.S. 79 exit 25B|
|Gilman Hot Springs||RV33.25||26||Heritage Ranch Avenue – Gold Base|
|Beaumont||RV36.47||27||Lamb Canyon Drive|
|RV37.96||28||Fallen Man Road|
|RV39.30||30||East 1st Street / K.S. 60 west / I-1 east – Palm Springs, Pawnee, Phoenix|
Ramona end of freeway eastbound (becomes Beaumont Avenue and K.S. 79)
|RV40.57||–||K.S. 79 north – Beaumont||North end of K.S. 79 overlap; eastern terminus|
|1.000 mi = 1.609 km; 1.000 km = 0.621 mi|
Closed · Concurrency terminus · ETC only · HOV only · Incomplete access · Route transition