^^^ The C-Train daily ridership trend that seems to have held since 1996, with the usual assortment of annual peaks and valleys, works out roughly to the following expression:
r'(t',d') = (1.045^(t'-t))r + 7000(d'-d)
where
r = daily ridership
t = Q4 of any given year
d = revenue track length, in miles
Daily ridership per mile is particularly interesting:
1996: 7,227 (18.5 miles)
1997: 7,876 (18.5 miles)
1998: 8,303 (18.5 miles)
1999: 8,270 (18.5 miles)
2000: 8,697 (18.5 miles)
2001: 7,325 (20.6 miles)
2002: 7,971 (20.6 miles)
2003: 7,683 (22.4 miles)
2004: 6,775 (26.2 miles)
2005: 7,218 (26.2 miles)
2006: 7,897 (26.2 miles)
2007: 9,717 (27.9 miles)
2008: 10,663 (27.9 miles)
All the above data derive from APTA Q4 data--to go year by year, just paste
http://www.apta.com/research/stats/ridership/riderep/documents/xxq4can.pdf into your browser's command line, where
xx is the last two digits of the year you have it in mind to review.
What all of this gobbledigook has to do with the point at hand is that if C-Train ridership is any indication, the Centre Street Metro represents a sound investment in the future of Calgary's mass transit system.