We consider the instance space metric method to the two-station single-track railway scheduling problem. This method has been effectively applied to several classical NP-hard scheduling problems, but was not tested on some actual railway scheduling models. It allows to construct the solutions with absolute error in polynomial time if there are some polynomially solvable instance subclasses for the initial NP-hard problem. Considering the metrics for the problem parameters space, we develop an innovative approach to solve the particular problem in polynomial time with absolute error and make some numerical tests.