Noun 片道 seemingly used as adverb

Question

大阪までは片道五千円です。 (It is five thousand yen one-way to Osaka.)

In the sentence above 片道 seems to be used adverbially (no particle, with a verb missing). According to jisho.org 片道 is not an adverbial noun, so I'm curious about its grammatical function here.

Is this a fixed expression somehow? Are there other examples of "ordinary" nouns used like this?

Answer 1

You can put various nouns in front of a number to indicate what kind of number it is.

• 合計100時間
  100 hours in total
• 累計100時間
  cumulative total of 100 hours
• 3個1980円
  1980 yen for three pieces
• 差し引き5万円, 差額5万円
  the difference of 50,000 yen
• 税込み700円
  700 yen including tax
• 税抜き700円
  700 yen without tax
• 先頭5人
  the first 5 people (in a waiting line)
• 最終1マイル
  the last one mile
• 西暦2021年
  2021 A.D.
• 時速88マイル
  88 mph
• 結成5周年
  5th anniversary (of a group)

I personally do not feel these nouns are temporarily being used as adjectives or adverbs. Perhaps we can just understand this as a common pattern.