My house is a long way

An example from Cambridge Dictionary:

We can use the phrase a long way to talk about distance:

My house is a long way from the station. You’ll have to take a taxi.

I easily fall into the following dilemma: "a long way" looks like a noun phrase, since it has a determiner, a modifier, and a head noun, following conventional analysis. What's more, Merriam-Webster indeed classifies "a long way" as a noun here.

Whether "a long way" is regarded as a noun phrase or simply as a noun, I tend to translate it literally as "a long distance" or even "an actual, physical road," and interpret "is" as "equals." This leads me to read the sentence as: "my house" (a concrete thing) equals "a long distance" or "a long road." I searched online but couldn't find any usage where "a long way" literally means "a physical road."

But the full sentence is "My house is a long way from the station," and the phrase "from the station" suggests that "a long way" is functioning adverbially, even though it is formally a noun phrase (or arguably a noun itself).

Besides, the original sentence can be rewritten as "My house is far from the station." In this context, "far" seems to serve the same function as "a long way."

So how should I identify "a long way" here?

1. Literally (form): a noun / noun phrase
2. Syntactically (function): an adveribial phrase
3. By replacement: (equivalent to) an adjective

• My house is [a long way from the station].

A long way is a noun phrase as it has the structure of one: head noun way, adjective as modifier long, determiner a. We can use other noun phrases in the same place, such as two kilometers, the same distance, etc.; and modify it just like any other noun phrase, like a pretty long way. And in general, spatial extent terms like this act as pre-head modifiers in the prepositional phrases.

The Cambridge Grammar of the English Language p644

(b) NPs indicating spatial and temporal extent

[26]

i We live [two miles / a few minutes’ walk beyond the post office].

ii It happened [ten minutes / a long time after the accident].

This is a common type of modification of PPs headed by spatial and temporal prepositions.

Note that neither of the following would be acceptable typically.

• *My house is a long way.
• *My house is from the station.

And we could have the entire phrase in other constructions where PPs are generally allowed, but not NPs, like existentials or as a post-head modifier in an NP.

• There is a little town [a long way from the station].
• [That little town a long way from the station] is called Whitehorse.

But not

• *There is a little town [a long way].
• *There is a little town [from the station].
• *[That little town from the station] is called Whitehorse.
• *[That little town a long distance] is called Whitehorse.

The spatial extent modifier is then required when the PP as a whole is denoting a distance/location rather than a source. Compare with verb of motion constructions or in a construction with a paired prepositional phrase headed by to or similar.

• The dog fled [from my house].
• [From my house to the station] is a long way.