(a) Before the district may construct an improvement across or under any railroad property, the district must notify the railroad authorities of the district's intention to construct the improvement if the railroad does not do so.
(b) The railroad has 30 days from the day it receives the notice in which to decide whether or not to build the improvement itself, at its own expense and according to its own plans.
(c) If the railroad builds the improvement, it must do so in a manner which is satisfactory to the district.