I suspect this question to be very simple but nevertheless, I don't understand why と is used here (in particular why not が or の (with the meaning of が)?)
交通事情により、表示の時刻と前後することがあります。
I suspect this question to be very simple but nevertheless, I don't understand why と is used here (in particular why not が or の (with the meaning of が)?)
交通事情により、表示の時刻と前後することがあります。
This 「と」 indicates the standard for comparison (and how something can deviate from that standard).
Standard: [表示]{ひょうじ}の[時刻]{じこく} "Times displayed"
Possible deviation: [交通事情]{こうつうじじょう}により[前後]{ぜんご}する "May not arrive/depart on time due to traffic condition"
「交通事情により、表示の時刻と前後することがあります。」
In this sentence, the subject for the verb 「前後する」 is unmentioned. The subject is not 「表示の時刻」, which is why one cannot use 「表示の時刻が」 as you suggest.
The unmentioned subject here is the "actual arrival/departure times". It is saying that those may deviate from the 「表示の時刻」.
The phrase to look for is 「A + が/は + B + と + (前後する)」 and in this case, the "A + が/は" part is left unsaid.