No one disputes this Australian state’s need to upgrade its rail-transit fleet after 40 years of service. The New South Wales regional train system in and around Sydney operates with a variety of trains, the oldest rolling stock – called V-sets – and newer XPT longer-distance carriers. After four decades, purchasing 512 new carriages at a cost of $2.3 billion had become a necessity. And with the purchase, commuters can look forward to mobile-phone charging stations, accessible toilets and more space for bike racks and luggage. All good … except for one rather major problem. The new trains are too...