Excellent point. I have read statistics that support this idea. The best place to train on a bike is probably the open road. You can usually ride faster, with fewer slowdowns on the road than you can on these MUPs.

I might add, if you're not yet comfortable riding on the road, there are times of the day when MUPs are less likely to be clogged with walkers in all their sizes and shapes. Around here, runners predominate in the early morning and at lunch time. Walkers and their even more obstructive kin, the inline skaters, rule in the afternoon if the weather is to their liking. Us cyclists are out in force in the evening.