Hence my comment about the hard pedaling and breaking...

It's a secondary road I choose to ride. I have two blacktop options. The fastest would be an 8 mile stretch of county road with no shoulder, it's fogline and then gravel shoulder. The other option has wide shoulders but there's a 7 mile stretch that's on a state highway with lots of traffic. It's safe to ride on with the wide shoulder but the noise can be deafening. The gravel option has better scenery, more wildlife and on a bad day I may be passed by 2 cars. I'm running 45's on my Disc Trucker which are awesome on gravel but slower on the pavement.

fifm

Like the OP, my main ride is a fixed, cyclocross style bike with 28mm commuting tires. With 72 gear inches, there are a few places where I spin out on the big downhills, I can only safely do 28 mph and that's with legs loose and just trying to keep up with the cranks. If I were able to coast down those at 30+, the 4mph uphills wouldn't bring the average down quite so much. Moving average is 12 miles per hour. Hoping that goes up as I get in shape. My best route currently is 90% trails or "parkway". The MUP is designed to keep bike speeds down to about 12 mph. Faster and you're putting yourself or others in danger. They're still the fastest way to get around, because it's a constant speed, vs the starting and stopping of traveling on roads.