Toronto’s current PATH system logo is often mistaken by tourists as 4 separate icons because it has 4 separate coloured letters, all with different fonts & enclosed in their own boxes. I’m a tour guide and many guests assume that one means “parking”, another “accessibility” another “hospital”, etc. Also, many people find the blue in the “T” very hard to see from a distance more than 3-5 meters away. It seems like changing the overall shape to be a circle, the shade of blue, and potentially the fonts would significantly improve how accessible & intuitive the sign is. 
Yours truly, a Tour Guide.