Best Practices for Rail Systems: Various Levels of Service

At times I’ve found it difficult explaining best practices for rail systems.  Germany is a great example, but it’s cost prohibitive to fly people over to Europe just to make my point.  One aspect that’s difficult for people to grasp are the various levels of service.  As a real-world example, let’s say we’re in the city of Köln (Cologne in English) and want to take a train to Hamburg around noon.

At 11:48, there’s an InterCityExpress (ICE) departing, which is Germany’s most expensive and most luxurious train.  At € 94 ($122), it’s pricey though.  Usually the ICE is the fastest train, but due to a transfer the 4 hour 17 minute trip is slightly longer than other options:

At 12:01, there’s a Hamburg Köln Express (HKX) departing.  Until recently all long-distance and commuter trains in Germany were operated by the government-owned Deutsche Bahn.  In the last decade or so, a partial privatization of the nationalized rail system has occurred allowing private companies to enter the market.  HKX is a private operator offering “no frills” bargain trains consisting of used passenger cars.  This video shows an HKX train departing Düsseldorf.  But at € 68 ($88), the HKX is a bargain, and the travel time of 4 hours, 7 minutes is competitive:
At 12:10, there’s an InterCity (IC) departing, which isn’t as luxurious or as fast as the ICE, but is still a nice train.  At € 89 ($115), it’s still pretty pricey.  The travel time of 4 hours, 2 minutes is the shortest:
At 12:21, there’s a local train departing.  In Germany, most of all the long-distance train network is also served by regional, rural, and commuter trains.  Traveling exclusively with these local trains is the most affordable way to travel, but it usually takes a lot longer with a lot more stops and several transfers to get to the final destination.  Traveling exclusively with local trains from Köln to Hamburg will take 4 transfers, and the trip will last 6 hours, 41 minutes, but the price is a bargain.  At € 44 ($57) for a non-refundable ticket and € 62 ($80) for a refundable ticket, it’s the most affordable option: