Looking at my recent app results, on my 2020 Trek FX3, I typically average about 15.5-16.0 mph throughout a 10-25 mile ride. Depends on crossings and other slow downs. Probably get as high as 24 mph on a slight downhill straightaway and slow to about 11 mph if uphill and with wind in my face. I'm in the far NW suburbs of Chicago and typically ride stretches of the Parairie/Fox River Trail from the Wisconsin border to all the way down to St. Charles (mostly paved with some sections of packed gravel).