Of course, we Germans have a statistic for this. On page 4 of http://www.bast.de/DE/Verkehrstechnik/Publikationen/Download-Publikationen/Downloads/V1-BAB-Tempolimit-2015-Kurzfassung.pdf?__blob=publicationFile&v=4 you can find that in 2015 18115 km of Autobahn don’t have a speed limit, additionally there are also divided highways without speed limit. But you also have to substract the many speed limits due to construction works. :wink: