Have you seen the green bike boxes on Garrison Street between Colfax and 1st Avenue? They alert drivers that cars are not allowed in that area and make the lane safer for bicyclists.
You've probably also seen sharrows. They are used on streets that do not have enough room for a bicycle lane to remind motorists to share the road with cyclists.
Traveling on the west side of the city? You'll find a new buffered bike lane on Denver West Parkway. It provides additional distance between vehicles and bicyclists.