Use of the MTA's buses and trains is down about three percent compared to last year. The agency says it's likely due to the recession and fewer people commuting to jobs, plus a fare increase last July, fluctuating gas prices and bus service changes. Despite Metro's attempts to put forth a rail face, buses are where the agency actually serves more people: about three bus boardings occur for every rail boarding on a typical weekday. (Rail use has come up on a percentage basis compared to a decade ago.)
Interesting how volatile bus ridership is by month, in this graph from Metro's blog The Source. Note December is the only month that boardings fall under one million per weekday:
Of the train lines, the Red Line subway is the busiest with a tad over 140,000 weekday boardings. Looks like it's all downhiill after June in both years shown.
The Blue Line is next in the rankings, with under 80,000 weekday boardings. As for the Green and Gold lines, well, average crowds at Dodger Stadium are bigger than the total daily use of either Metro train line. The Orange Line busway across the Valley trails the pack at about 25,000 boardings a day, based on eyeballing the MTA's graphs.