[[File:WFB ET 609-III.jpg|thumb|A [[Stadler KISS]] trainset in [[Rheine, Germany]], similar to the type ordered by Caltrain.]]
The Stadler KISS double-decker EMU that Caltrain ordered will have Crash Energy Management (CEM) feature and be compliant with [[FRA]] alternative Tier-I crash-worthiness standard. Coupling with [[Positive Train Control]] (PTC) system that will be installed on the Caltrain line, allowed for mix operation with trains that are compliant with standard Tier-I standard, such as Amtrak passenger trains and Union Pacific freight trains. <ref>{{citeweb|url=https://wwwstadlerrailcom-live-01e96f7.s3-eu-central-1.amazonaws.com/filer_public/21/81/21816a39-9448-4b8a-8f2f-3811c6ee8006/kcal0716us.pdf|title=KISS Double-Decker Electric
Although Stadler's trains are built to European crash standards rather than U.S. [[Federal Railroad Administration]] (FRA) standards, Caltrain received a waiver from the FRA to operate its electric trains in mixed traffic with diesel and freight locomotives. The waiver, a first in the United States, was granted due to Caltrain maintaining temporal separation between its passenger service and freight traffic, as well as its development of a collision mitigation and avoidance plan.<ref>{{citeweb|url=http://www.railwayage.com/index.php/news/caltrain-lands-fra-waiver-for-passenger-operations.html|title=Caltrain lands FRA waiver for passenger operations|publisher=''[[Railway Age]]''|date=June 1, 2010|accessdate=March 29, 2017}}</ref><ref>{{citeweb|url=http://www.progressiverailroading.com/passenger_rail/article/At-Caltrain-running-electric-multiple-units-is-a-key-component-of-the-agencys-long-term-growth-plans--32040|title=At Caltrain, running electric multiple units is a key component of the agency's long-term growth plans |author=Cotey, Angela |date=July 2007 |magazine=Progressive Railroading |accessdate=March 29, 2017}}</ref>
Multiple Unit EMU|Publisher=[[Stadler Rail]]|accessdate=April, 4, 2017}}</ref>
