express surcharge; express charge
The additional fee required to ride an express train (急行) beyond the base fare.
急行料金は乗車券とは別に必要です。
The express surcharge is required separately from the basic fare ticket.
Refers specifically to the limited express surcharge, which is usually higher than the express surcharge (急行料金).
The basic fare ticket; 急行料金 is an additional charge on top of this.
Compound of 急行 (express train) and 料金 (fee, charge).