My guess would be that the rail line would need entirely new right of way which would radically increase the variability of the cost and may result in it being

My guess would be that the rail line would need entirely new right of way which would radically increase the variability of the cost and may result in it being down right impossible. (Speaking as someone who closely watched the drama around getting new right away along I5 for high voltage transmission) While the highway expansion probably already has the land they need for most of the project.