Speed Limits on Autobahns




In Germany the discussion about an introduction of a general speed limit on freeways has rekindled. Again. Should it be introduced or not?

The autobahn A45 in Dortmund-Oespel and the road sign for “all restrictions lifted”.

The green party has announced their intent to bring the matter into the parliament to be voted on for the first time1.

To recapture, if you’re not from Germany: Currently on German freeways (“Autobahnen” in German, or “autobahns” if you use the english plural) there is no general speed limit. We have a so-called “Richtgeschwindigkeit”, which you could translate as “recommended maximum speed”. In practice that means: You can drive as fast as you want.

The Richtgeschwindigkeit applies on about 70 % of the freeway network, the rest is limited with speed signs. This lack of a speed limit is globally unique.

This even produces “speed tourism” – there are tours to Germany where a joyride in a well-motorized car over some unlimited freeways is the main attraction. A fitting anecdote: The A555, the oldest German freeway, is known as “Diplomatenrennbahn” (“diplomat race track”). This is because Bonn, the city it starts in, was the capital before reunification and therefore housed a lot of embassies and diplomats. These liked to drive with top speeds over the unlimited and quite straight freeway route.

The whole debate is quite emotional. Germany is a nation of car drivers, many Germans love their cars, which makes it hard to get down to a rational level – but I’ll try.



The most prominent pro argument. A lower top speed leads to a lower rate of crashes, injuries and deaths. And it’s a fact that the rates do decline. On freeway stretches that were unlimited which then had a limit imposed, crash rates dropped significantly. A study by the Brandenburger Landesbetrieb Straßenwesen (state service for road matters) puts a number on it: After allowing for traffic amount, the introduction of a limit decreased the amount of crashes on a Brandenburger freeway section by 26.5 %2.

Even on an purely economic level this is beneficial: The study concluded that the costs saved by the lower crash rate are higher than the costs imposed by higher travel times.

And please consider: Some people (like the Bild “news”paper3, the German equivalent of The Sun) state that whether you crash at 130 or 160 km/h is irrelevant, you die anyway. While that is (mostly) true, it’s the amount of crashes that decreases considerably. The conclusion that a limit doesn’t prevent deadly crashes is just plain wrong.

Yes, German freeways are very safe. Safer than most, even without a limit. And yes, most crashes don’t happen on freeways, but on rural and urban streets. But that does not change the fact that a speed limit could further decrease the crash rate significantly. While this shouldn’t lead us to go to an emotional level (“You’re against a speed limit? DO YOU WANT PEOPLE TO DIE?!”, which is a way of argumentation which would lead us to have to outlaw kitchen knives), this must definitely be considered.


A nice side effect of speed limits is an increase of capacity. That might seem counter-intuitive – shouldn’t a faster speed mean more cars per time unit? But faster speeds also mean higher distances between cars and higher speed differences between lanes which makes entry, exit and lane changing less fluid. It also means less reaction distance, more frequent braking and acceleration, which provoke congestion.

The aforementioned study4 confirmed this (take that with a grain of salt though, this is hard to measure and they couldn’t deduce a general correlation). While the numbers are less significant than the decrease in crashes, it’s still to be considered.


Of course a speed limit would also reduce the amount of energy (and therefore gasoline) spent and therefore also the amount of emissions like climate gases.

The actual reduction amount is not an easy thing to measure. A study by the Umweltbundesamt (federal department for environment) concluded that a limit of 120 km/h (currently debated is mostly 130) would decrease the amount of CO2 emitted on freeways by 9 %5. Applied to all road traffic that comes down to 2 %. The study is from 1999 though, sadly I couldn’t find anything more contemporary.

That’s not a whole lot, yes, but it’s more than nothing. And it’s definitely not productive to belittle CO2 reductions. There is just no single big thing that would significantly reduce emissions in one blow with little expense – all realizable possibilities are small if viewed by themselves, and we have to start somewhere.

It’s also sometimes suggested that a general speed limit would lead to smaller and less motorized cars being sold as high speed wouldn’t be needed anymore. I don’t think that would be the case though. Big SUVs are already booming and not because of their speed. And just look at the United States where the highest speed limit is 85 mph (137 km/h), and still the preference for big and well-motorized cars is even more prevalent than in Germany.

Public Opinion

In various current surveys a majority of Germans (not by a huge margin, around 55 % depending on the particular survey, but still) are in favor of a general speed limit6.

All the others have one

Well, while generally I don’t think this is a valid point (or as my mother would say it: “If everybody else jumps from a skyscraper, would you jump as well?”), the current situation causes the “speed tourism” I mentioned in the beginning. I think stopping that would be a good thing.



A general speed limit would of course increase travel times, and on long distances noticeably so. Still, the average speed decreases less than one would expect: The study mentioned above recorded a change from an average car speed 142 km/h on a six-lane unlimited freeway to 132 km/h. Still, this is to be factored in.


I don’t think this one needs any further explaining.


The most prominent argument against a general limit includes the previous ones in a way: it’s that of freedom. As a libertarian, I’m sensitive to questions of restrictions on freedom. But the thing is:

Fast driving on public streets is not a personal or civil liberty.

It’s the difference between outlawing running around naked in your home, that would definitely be against personal freedom, and outlawing running around naked at a bus stop. That last one is already outlawed – and rightly so.

You can always go to a private racetrack and drive there as fast and even as dangerously as you want. But public streets are, as the name suggests, public. The state has the right, and the duty, to regulate their usage so it’s fair and safe to everyone. All other traffic rules are examples of that. Or would you say that a stop sign impedes your liberty? Even in a libertarian society, where streets would be privately or cooperatively operated without a state, the same thing would apply.

That of course doesn’t mean the pros shouldn’t be weighed against the lost time and fun, but please don’t try to make this a question of liberty or civil rights. It’s not.


As you might have guessed from my header image (at the time of writing it’s a freeway), I’m not impartial to the issue. I like freeways and I like driving. I also drive faster than 130 km/h sometimes and yes, I enjoy it.

But still – considering the arguments for a limit, which are numerous and significant, the contra arguments simply can’t stand. The loss of time is more than compensated for in less crashes, economically and humanistically, and the other pro arguments definitely trump the “fun” point.

So while I’m not happy to say it, yes, I think a general speed limit should be imposed.

  1. Source↩︎

  2. Source (German, the PDF seems to be broken in Chromium, try an external reader), Article summarizing the study, it also refernces a similar situation in Nordrhein-Westfalen (German)↩︎

  3. Source (German, BildBlog is a critical blog about German media)↩︎

  4. Source (German, the PDF seems to be broken in Chromium, try an external reader), Article summarizing the study, it also refernces a similar situation in Nordrhein-Westfalen (German)↩︎

  5. Source (German), Article summarizing the study (German)↩︎

  6. Source (German, BildBlog is a critical blog about German media)↩︎

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