The Foothill Freeway is the name assigned to Interstate 210, a 'bypass' interstate about 70 miles long located in the Los Angeles Metropolitan area. Bypassing central Los Angeles via a generally west to east alignment, this freeway links many of the suburban cities and communities that surround Los Angeles to its north and east. This freeway also allows access to the San Fernando Valley (a district of Los Angeles), without having to pass through the more heavily traffic congested downtown area.
As its name implies, its alignment is along the foothills of the San Gabriel Mountains. The freeway is not complete; there is currently a 10-mile gap in San Bernardino County. After a lengthy hiatus, construction on the segment of the freeway between its junction with the Orange Freeway, California State Highway 57 (CA/SR-57) in San Dimas and the Ontario Freeway, Interstate 15 (I-15), in Rancho Cucamonga was finally completed in late 2003. At this time, the segment between the I-15 and Interstate 215 (I-215) in San Bernardino is ongoing and is expected to be completed by 2010. When completed, the freeway will provide another link between the communities of the Inland Empire and the Los Angeles area.
The Foothill Freeway west terminus is at the junction with the Golden State Freeway, Interstate 5 (I-5), near Sylmar, a district of Los Angeles, at the foothills separating the San Fernando and Santa Clarita valleys. From that point, the freeway's alignment is generally diagonal as it heads southeast through the northeastern San Fernando Valley and the Crescenta Valley before turning due south towards the junction with the Ventura Freeway, California State Highway 134 (CA/SR-134) in Pasadena. At this interchange, the number assignment of I-210, somewhat confusingly, 'transfers' to the alignment of CA/SR-134. The physical alignment of the freeway continues south, however, ending at California Boulevard. Interstate 210 then becomes an east-west freeway (the CA/SR-134 number assignment is dropped east of the interchange). The freeway's alignment continues east until its junction with Interstate 15. About four miles east of the interchange, the freeway ends at Sierra Avenue in Fontana (as of early 2005).
Prior to late 2003, the Foothill Freeway's 'numbered' alignment 'transferred' to what is now the Orange Freeway California State Highway 57 (CA/SR-57) in San Dimas - although the physical alignment, as in Pasadena, continued, in this case, eastward as California State Highway 30 (CA/SR-30). Prior to late 2003, I-210's alignment was north-south after the junction in San Dimas and terminated at its intersection with the San Bernardino Freeway, Interstate 10 (I-10), the Orange Freeway, California State Highway 57 (CA/SR-57), and the [[Chino Valley]/Corona Freeway (California State Highway 71]] (CA/SR-71) at the Kellogg Interchange complex.
However, in late 2003, a 20-mile segment of the Foothill Freeway east of San Dimas was completed and the I-210 numbered assignment was transferred back to the east-west segment noted above, and the CA/SR-57 number assignment replaced the I-210 number assigment.
The segment of the Foothill Freeway between its western terminus near Sylmar and what is now a southern spur in Glendora is signed as Interstate 210. (The former southern spur has since been re-signed as California State Route 57, although it has not yet been designated as part of the Orange Freeway.) The eastern extension is signed as California State Route 210 between the southern spur and the Escondido Freeway, and as California State Route 30 from there to its eastern terminus in Redlands. Caltrans has petitioned the AASHTO, the federal body that oversees the interstate highway system, to re-sign the entire Foothill Freeway as I-210; this petition is unlikely to succeed until the eastern extension is complete.
Cities/Communities located along the Foothill Freeway (west to east)
Major Freeways/Highways intersecting with the Foothill Freeway (north to south)