I ride all over Denver, if you want to ride, RIDE ... as with any urban riding, you as the RIDER have to keep your eyes peeled, avoid busy streets, find good side street routes ... in Chicago, I'd hop on a busy street only as long as I had to or there was a good path to do so.  It still was the most dangerous part of every commute, higher speeds for cars and low bike speeds don't mix well.

26th and 29th coming from the West burbs into the city BOTH have received lanes in the last few years.  Denver is getting better ... but I ride whether there is a path or not!

Another strategy I used in Chicago : I'd keep clothes at my cube downtown carried on from 'L' rides days, ride in bike clothes down and back.  Use the showers at the Chicago Athletic Club which was around the corner from the Wrigley Building.  I charmed the security guards at the Chicago Tribune building to let me in after showering and changing, and eat at the employees only cafeteria.  The omelettes there were AWESOME .. :)