D.C. Code § 9-303
The entire cost of paving, repairs, or replacements incident to track repairs, replacements, or changes made at a time when the bridge is not being paved, and one-half the cost of other paving, repaving, or maintenance of paving between its track and for 2 feet outside the outer rails, and the excess cost of construction and maintenance of any bridge across Rock Creek due to the existence or installation by a street railway or railways of its or their tracks on such bridge shall be borne by the said railway company or companies, and shall be collected in the same manner as the cost of laying pavements between the rails and tracks of street railways as provided for in § 9-401.01. The amounts thus collected shall be deposited to the credit of the appropriation for the fiscal year in which they are collected.
D.C. Code § 9-303