Though published by the City Club, the 1914 through-routing scheme was the work of Bion J. Arnold, a famous transit expert of the day. Over the years, I've posted it several times:
Here's the full report.
But, of course, now we're talking about a half-billion-dollar tunnel—not necessarily electrification. Dual-mode diesel-electric locomotives could run through a tunnel just fine, without needing to string wires over 60 miles of UP-N tracks.
When the Metra Electric overhead needs to be replaced (it's now 92 years old), we'll have a tough decision to make as to whether it's even worth keeping.