To resolve this enigma, first some simple maths: the company property between Market and Wabash Street was 195ft wide. the Terminal building was
164ft 163.8 wide. So a total of 31ft 31.4 ft are remaining north and south of the building. If the strip north oft the building was perhaps 21.4 ft wide, the distance to the alignment in Market Street could be 11ft 10 ft. Does anybody have more exact data?
There is one photo (http://www.shorpy.com/node/3084) who gives me a chance to try a check. This image is of considerable interest, not only for the street scene. As this photo was taken in 1943, tracks were removed, but the terminal was not altered. No other photo shows the "dead angle" of the terminal like this one.
I draw some auxiliary lines over the photo. If the man with his hat was 6ft high, the strip south of the terminal was 10 or 11 ft wide. Experts will calculate more exact, perhaps using the diameter of a vintage Greyhound bus wheel...