Living in Germany, high speeds are luckily allowed and I can drive as fast as my Mazda can do quite often. About half of the Autobahns (motorways, highways) are still without speed limits.
I need to visit city of Solingen in the western Germany quite often, door to door it is 472 kilometers (about 294 miles), over four fifths of it no speed limit. I especially like the relatively new A38 Autobahn which since a few years now have made this trip 50 kilometer (about 31 miles) shorter and which is almost totally in its length of 200 kilometers (about 124 miles) without speed limits, a 130 kmph (80 mph) limit only in couple of bigger exits / junctions. I usually need about 3 and a half hours for the trip, including a coffee / cigarette break halfway through (although a smoker, I have never smoked inside my car or home excluding my study). It makes an average speed of 143 kmph (89 mph), even a bit more as that average does not take into account the break.
This screenshot from my Nokia N900 Navi's Trip Details shows I need less than 40 minutes to drive to visit my friend and coworker who lives 90 kilometers (56 miles) away:
Notice that that's door to door; I have to drive slowly through the city first about 6 kilometers (3.7 miles) of that 90 to get to the Autobahn, then about 10 kilometers (6.2 miles) from the Autobahn into small roads leading to the village where he lives. The average speed 139.19 kmph (86.5 mph), top speed 210.17 kmph (130.6 mph).