49 CFR 1242.15: Roadway, tunnels and subways, bridges and culverts, ties, rails, other track material, ballast, track laying and surfacing, and road property damaged (accounts XX-17-10 to XX-18-12 inclusive, 21-17-13 to 21-18-16 inclusive, XX-17-17, XX-18-17, XX-17-48, and XX-18-48).

The expenses for running and switching subactivities shall be separated between freight service and passenger service as follows:

(a) Switching tracks. (1) Yard: Expenses for yards used in common by freight and passenger services shall be apportioned on the basis of the respective switching locomotive unit-hours in the common yards.

(2) Way: Where the tracks at any one location are used in common by both freight and passenger services, expenses may be assigned to that service which makes the dominant use of them.

(b) Running tracks. The expenses of tracks used in common by both services shall be apportioned on the basis of gross ton-miles (including locomotive ton-miles) handled over these tracks in the respective services.