The German state of Bremen has implemented a speed limit on the Autobahn. The speed limit applies to only six kilometers (3.7 miles) of the highway, all within Bremen. The speed limit is 120 kilometers per hour (about 75 miles per hour).
Many people want to impose a speed limit on the entire Autobahn, both for safety and environmental reasons. In most countries, I don’t think a speed limit would be an issue, but it is very controversial in Germany. Interestingly, the public seems to be evenly split on the idea. I suspect that they would have been heavily opposed just a few years ago.