I've lived in the Barrington area for years, and while CN can certainly block traffic, it's not as bad as the article portrays it.
The first responders know to how to get around things, and even when the in-town crossings are blocked, they're not necessarily blocked at Ela, and if they are, it's a quick jog over to Deerpath and the Route 12 underpass.
Barrington doesn't want to pay for an underpass, the State doesn't have the money, and CN knows they don't have to pay for it because they were there long before US-14 was.
The best solution isn't an underpass --- it's a grade separation over the UP, from south of Lake-Cook and on piers/embankment/viaduct all the way past US-14. Both are fairly busy, and the underpass only benefits one side of town.
CN already has the ROW, and building adjacent to the existing tracks is probably cheaper than the current plan for the underpass, which involves land acquisition and tearing down part of a neighborhood plus rerouting a creek.
They could probably apply for a CREATE grant...