I typically find that my mood seems to affect the speed of travel more then anything else. Sometimes I just want to reach my destination(s) for the day as quickly as possible so that I can partake of some activity that I've been looking forward to. These stops could be museum visits, historical sites, lunch stop etc.
Other times I just enjoy pedaling slowly and taking my time, breathing in the peace and quiet and enjoying my opportunity to be away from normal life.
During my recent "A Breath of fresh air tour" I traveled 95.5 km in 4 hours and 11 minutes on Day One and 95.0 km in 4 hours and 56 minutes on Day Two. This was a lightly loaded tour to a friend's home in a nearby city.
During my Round Lake Erie tour I averaged 120 km/day for distance. This was a fully loaded/self-contained tour and my fitness level was better then it is today. I was also lighter! Two examples from that tour include 111.5 km in approx 4.5 hours, and 178.44 km in 7 hours and 54 minutes.
During my Round Lake Huron tour 103 km in 5 hours, 6 min, 169 km in 8 hours and 5 minutes. Again fully loaded.
These are all actual pedaling times and are not total elapsed time. If you actually factor in all my stops for pictures, food, siteseeing etc then in reality my day starts around seven am and ends around dark.
Other factors that can definately influence your speed include winds, attitude, food, terrain, road surface, load distribution etc.
I don't worry about speed too much. Generally I aim for an average speed of 20 km/hr. Sometimes I am below that speed and sometimes I am above. I love to ride but I don't let any need for speed slow down my urge to look around when I'm on the road.
I think it's fair to say that when I tour it's about the journey rather then the destination. I suspect many people feel the same way.
~Jamie N
www.bicycletouring101.com