For time purposes I usually do two rides/workouts a day. Not really any different IMO than doing a single longer workout. If I am going to do intervals or something hard at lunch or in the evening I may just ride SST or tempo in the morning.
I did 3 rides many days last year but this year with doing a lot more intensity it hasn't worked out too well the few times I tried it
SST in the morning+hill interval group ride at lunch=pulling out of windy practice crit
Thanks for the info everyone. This was pretty much what I was thinking of doing.