Just another example why average speed is the wrong metric. Tonight I rode for an hour; did time trial intervals, 4x8. My average speed was only 18.2mph, but it was a very hard workout.

I could have easily averaged 21-22mph with less effort, but would not have targeted what I wanted to work on, or got as much benefit from the workout.

So telling you I average 18.2 mph really tells you nothing useful.