Don't know about Chicago's, but the ones I've seen have restrictions on time of usage, usually after rush-hour, which makes those types of fare systems unusable to the majority of riders.
I can't remember if NYC also raises rates during rush hour, but D.C. does as well.
I think I stopped taking the D.C. system when a single day's transit and parking started topping $13/day.
Don't know about Chicago's, but the ones I've seen have restrictions on time of usage, usually after rush-hour, which makes those types of fare systems unusable to the majority of riders.
I can't remember if NYC also raises rates during rush hour, but D.C. does as well.
I think I stopped taking the D.C. system when a single day's transit and parking started topping $13/day.