この道路は工事中につき通行できません。
- This road is closed due to construction.

この道路は工事中につき通行できません。 meaning: This road is closed due to construction.

The sentence follows a common Japanese structure: Topic - Information/Explanation. ⚫︎ この道路 (topic marker: は) - identifies the topic of the sentence, "this road." ⚫︎ 工事中 - indicates the current state, "under construction." ⚫︎ につき - expresses the reason or cause, "due to." ⚫︎ 通行できません - presents the result or consequence, "cannot pass."

につき is a conjunction used to indicate the reason or cause for something. ⚫︎ It is a more formal and written style equivalent to ので or から. ⚫︎ It is often used in announcements, notices, and formal writing. ⚫︎ Structure: [Reason/Cause] につき [Result/Consequence]. For example: ⚫︎ 悪天候につき、明日の試合は中止になりました。 - Due to bad weather, tomorrow's game has been canceled. ⚫︎ 会員以外の方につき、ご利用できません。 - Due to being other than members, cannot be used.

工事中 is an adjectival noun (な-adjective) modifying the topic この道路。 ⚫︎ It literally means "under construction." ⚫︎ Adjectival nouns describe the state or condition of a noun. ⚫︎ They take the particle な before a noun they modify, although, in this specific sentence, the な is omitted. For example: ⚫︎ 静かな図書館 - a quiet library. ⚫︎ 元気な子供 - a healthy child. ⚫︎ When 工事中 is used to describe a noun (e.g., 道路), it functions as an adjectival noun without the な.

The verb 通行できます "can pass through/use" (potential form of 通行する) is conjugated to express ability or possibility. ⚫︎ 通行する (to pass through/use) is a suru-verb. ⚫︎ The potential form is created by changing the dictionary form of the verb to the -れる or -られる form. In this case, it changes to: 通行できる。 ⚫︎ 通行できます is the polite (masu-form) affirmative form. ⚫︎ 通行できません is the polite (masu-form) negative form. For example: ⚫︎ 日本語が話せます。 - I can speak Japanese. ⚫︎ この部屋ではタバコを吸えません。 - You cannot smoke in this room.

The particle に has multiple uses. In the sentence 工事中につき, に is implied, and therefore, it is part of the fixed expression につき. ⚫︎ In the context of につき, に marks the reason or cause in a more formal style. ⚫︎ It's often used with noun phrases or adjectival nouns to indicate the reason. For example: ⚫︎ 停電に（つき）、電車が止まりました。 - Due to the power outage, the train stopped. (Here, 停電 is a noun) ⚫︎ 満員に（つき）、入場できません。 - Due to being full, you cannot enter. (Here, 満員 is an adjectival noun)