If that's the line passing through Champaign, IL, it was complete in central Illinois around 1989-1990.
OK thanks guys. Yes, I think it was definitely connected with "rationalizing." But the late 1980s would have been quite late. Ripping out double track and replacing it with CTC single track mostly occured in the early 1970s, as I understand it, the nadir of the American railroad industry when things looked bad. PS Pachyderm, I live in Champaign.
The previous poster is correct, the IC main was converted from double to single track in the 1988-89 period, not the 1970s.
"Trains" magazine, I think, had a feature on why IC decided to convert its double-track main (through Champaign and Rantoul on to the north) to single track with several passing sidings sometime in the 1988-91 time frame, IIRC. Part of the story was that the president found the railroad would save money on taxes by not having so much track or something like that. GTW did much the same, according to the story, but other roads were adding track because of the business. I haven't seen that article in years and may have some details wrong but that's how I recall how the trend started.
Making double track current of traffic signaled lines into single track CTC lines was a 'go to' for many carriers starting in the late 1950's and early 1960's. Save on taxes and save on the manpower and materials required maintain the line. Of course, during that period of time 'Deferred Maintenance' was the bean counters battle cry to management - use it until it fails.
