"The story of the railway switchman illustrates the substitutionary nature of Christ's death, but gives a distorted portrayal of God's will and God's law. The switchman (representing God the Father) is compelled to make a choice between two distinctly unpalatable options, and the decision is forced upon him by the pressure of unforeseen circumstances. His son is an unfortunate, passive victim who has landed himself and his father in this dreadful situation by sheer carelessness, and he does not willingly consent to die. This contrasts starkly with the biblical picture of the cross as part of God's eternal plan, devised before the creation of the world to glorify the Son; of the Father as the one who deliberately chose to send his Son into the world; of the Son as the willing, determined, self-giving Savior of his people".
Pierced for Our Transgressions:
Rediscovering the Glory of Penal Substitution (page 332-333)
Steve Jeffery, Mike Ovey and Andrew Sach