These routes represent some of the more popular and well-traveled paths in the metro DC area.  They are popular with recreational walkers, joggers, cyclists, and commuters, so they tend to be fairly populated at most times of the day.  The terrain is generally even and maintained on all of them.  With the exception of the Rock Creek Trail, these paths are good options for any of the following workout types: long distance runs, daily maintenance runs, tempo and pace runs, and fartlek speed play workouts.