To add a bit, it should also be noted that many of the reliability issues that passenger diesels have are related to emissions equipment. Industrial diesels engines are not required to have all the fickle equipment, so they are generally much more reliable.
So buses and trains have significantly longer service lives and lower operating costs than passenger diesels do. Turns out, diesel engines are wonderful when you don't care about emissions.
To add a bit, it should also be noted that many of the reliability issues that passenger diesels have are related to emissions equipment. Industrial diesels engines are not required to have all the fickle equipment, so they are generally much more reliable.
So buses and trains have significantly longer service lives and lower operating costs than passenger diesels do. Turns out, diesel engines are wonderful when you don't care about emissions.