Editing Cajon Pass (section)

=== Traffic ===
[[File:Santa Fe R.R. trains going through Cajon Pass in the San Bernardino Mountains 1a34758v.jpg|thumb|Santa Fe train climbing to Cajon Pass 1943]]
[[File:UP 9214 19910510 CA Cajon.jpg|thumb|[[Union Pacific Railroad]] [[GE Dash 8-40C]] #9214 leads a freight train up Cajon Pass]]
[[File:844 nov 19 2011 036xRP - Flickr - drewj1946.jpg|thumb|Union Pacific excursion train at Cajon Pass pulled by [[Union Pacific FEF Series|FEF-3]] [[4-8-4]] "Northern" type [[steam locomotive]] [[UP 844]]]]

The [[California Southern Railroad]], a subsidiary of the [[Atchison, Topeka and Santa Fe Railway]], was the first railroad through Cajon Pass. The line through the pass was built in the early 1880s to connect the present day cities of [[Barstow, California|Barstow]] and [[San Diego]].<ref>{{cite book| author=Waters, Leslie L.| title=Steel Trails to Santa Fe| year=1950| publisher=University of Kansas Press| location=Lawrence, Kansas| pages=131–133 }}</ref><ref>{{cite book| author=Serpico, Philip C.| title=Santa Fé Route to the Pacific| year=1988| publisher=Omni Publications| location=Palmdale, California| isbn=0-88418-000-X| pages=18–24 }}</ref> Today the [[Union Pacific Railroad]] and [[BNSF Railway]] (the successor to the Santa Fe) use the pass to reach Los Angeles and San Bernardino as part of the [[Southern Transcon]]. Due to the many trains, scenery and easy access, it is a popular location for [[railfan]]s, and many photographs of trains on Cajon Pass appear in books and magazines.

The Union Pacific Railroad owns one track through the pass, on the previous Southern Pacific Railroad Palmdale cutoff, opened in 1967. The BNSF Railway owns two tracks and began to operate a third main track in the summer of 2008.<ref name="BNSFCAJON">{{cite web |last=Ghori |first=Imram |url=http://www.pe.com/localnews/transportation/stories/PE_News_Local_D_rail14.3f1cf86.html |title=Railway aims to add track through Cajon Pass |publisher=Riverside Press-Enterprise |date=August 15, 2007 |access-date=April 30, 2008 |archive-date=May 20, 2011 |archive-url=https://web.archive.org/web/20110520023238/http://www.pe.com/localnews/transportation/stories/PE_News_Local_D_rail14.3f1cf86.html |url-status=dead }}</ref> The railroads share track rights through the pass ever since the Union Pacific gained track rights on the Santa Fe portion negotiated under the original [[Los Angeles and Salt Lake Railroad]]. The original BNSF (ATSF) line was built in the 1880s and later roads, [[U.S. Route 66]] and I-15, roughly followed this route. The 3.0% [[grade (slope)|grade]] for a few miles on the south track is challenging for long trains, making the westbound descent dangerous, as a runaway can occur if the engineer is not careful in handling the brakes. The second track, built in 1913, is {{convert|2|mi|km}} longer to get a lower 2.2% grade. It ran through two short tunnels, but both were removed when the third main track was added next to the 1913 line.<ref name="BNSFCAJON" />  Trains may be seen traveling at speeds of {{convert|60|and|70|mph|abbr=on}} on the straighter track away from the pass, but typically ascend at {{convert|14|to|22|mph|abbr=on}} and descend at {{convert|20|to|30|mph|abbr=on}}.<ref name="BNSFCAJON" /> With the third track, the BNSF lines have a capacity of 150 trains per day.<ref name="BNSFCAJON" />