Learn English – Zero Article in Family Names

The terms "a countable noun" or "an uncountable noun" don't work well applied to given words, but rather to given uses. Note that those dictionaries that state whether a noun is countable, uncountable, or both, will often do so per sense rather than per lemma.

"The use of apple" would have been perfectly valid; it would apply to apple as a substance. Likewise "instead of pears" would also have been valid, referring to the fruit as individual, countable items, rather than as a substance. Indeed, some would disapprove of the sentence mixing the two different approaches; preferring either "apples instead of pears" or "apple instead of pear".

Hotel and situation are both being used as countable nouns, to modify the (countable) noun change to indicate what the change is of. In this case we use the singular because we need to change one hotel or one situation (that we need to change it for another hotel and situation respectively, does not affect this). If I was concerned with several hotels (say I was organising a conference and therefore had to deal with more than one) I might express a desire for "a change of hotels".

Even though we are using them as countable, we don't use an article, because of their modifying role. It's comparable to how we would say "a trouser press" (the article applies to press not to trouser) or "trouser presses" (no article because presses is plural, singular trouser used even though trousers is normally plural).

In the UK, we give names to "lines" or routes rather than the train. The definite article is usually used in normal speech, for example "The Victoria Line". A search for "Victoria Line" reveals that this is almost universal in most kinds of texts such as news reports, discussions by or about passengers, services, railway administration.

In timetables and also their announcements of engineering works, delays, etc, the train companies seem to avoid the definite article by using a written style that is less discursive and which uses formatting that favours brief titles (displaying the name of a line simply as "Victoria Line", for example). Extensive examples can be compared on the Transport for London website.

The only named train I can think of offhand is Eurostar. This could, in normal speech, refer to either the services or to the physical trains that it uses and which are highly distinctive to it. We talk of "taking the Eurostar" but also of "going by Eurostar". British people wouldn't assume this referred specifically to either the physical trains or to the institution and context would be the guide. Nevertheless, as seen on the Eurostar website, the definite article is largely avoided by the operators and the name is used in the manner of a brand name.