Eğer asfalttaki çatlak tamir edilmezse, şeritler karışabilir.

If the crack in the asphalt is not repaired, the lanes could become mixed up.

Breakdown of Eğer asfalttaki çatlak tamir edilmezse, şeritler karışabilir.

• tamir edilmek: to be repaired
• eğer: if
• -ta: in
• -ki: that

Questions & Answers about Eğer asfalttaki çatlak tamir edilmezse, şeritler karışabilir.

What is the function of Eğer in this sentence?

Eğer means “if” and introduces a conditional clause. In Turkish it’s actually optional: the conditional suffix -se on the verb already signals “if.” You could therefore say
Asfalttaki çatlak tamir edilmezse, şeritler karışabilir.
without Eğer, and the meaning stays the same.

How do we form the adjective asfalttaki, and what does it mean?

asfalttaki breaks down as:
• asfalt (asphalt)
• -ta (locative case, “in/on/at”) → gives asfaltta (“in the asphalt”)
• -ki (relative suffix, “that is…”) → gives asfalttaki (“the one in the asphalt”)
So asfalttaki çatlak means “the crack in the asphalt.” The doubled “tt” comes from consonant assimilation: asfalt + -ta → asfaltta.

Why is tamir edilmezse in the passive voice, and could we say it actively?

Using the passive edilmek (“to be done”) focuses on the action (repair) rather than the person doing it. Tamir edilmezse means “if it is not repaired.”
You can make it active by saying:
Eğer asfalttaki çatlağı tamir etmezlerse, şeritler karışabilir.
Here tamir etmezlerse is “if they don’t repair,” and çatlağı takes an accusative ending to show it’s the direct object.