German Autobahns

[Rothman]

Regarding the Schoharie bridge collapse, that was not due to being cheap, but rather just poor engineering and not supporting the pedestals deep enough into the crappy soil under the bridge.  I would consider that mistake much more grievous than simply choosing the cheapest alternative, which may actually be a good thing if chosen properly.

I also think of the Big Dig roof collapse, which was due to a contractor going too cheap on the materials involved and not meeting the specs.  There is a circle of Hell waiting for them.  Again, not about cheapest viable alternative, but, in this case, insidious rogue cost-cutting.

[jemacedo9]

It's for the short merge area and narrow to non-existent shoulders that I would find European freeways VERY intimidating to drive. 

Come south to PA for a little while and build up your tolerance...!   

[J N Winkler]

German standards for horizontal curvature on the Autobahn are much stricter than those that apply to Interstates.

There is still some Reichsautobahn alignment here and there. Sometimes they just expanded the existing road without major changes in alignment. And then there are still a a few original 1930s style Reichsautobahnen remaining, most notably portions of A8 in Southern Germany. They have no shoulders and tight curves.

I have personally never driven the A8, so I don't really understand what people are talking about when they say it has tight curves.  The 1933 engineering standards called for minimum horizontal curve radii of 1800 m (1200 m), 1000 m (800 m), and 600 m (400 m) in flat, rolling, and mountainous terrain respectively (values in parentheses refer to absolute minimum values that could be used only exceptionally).  In comparison, Interstate standards in 1944 called for maximum curvatures ranging from 2.5° to 9° depending on design speed and terrain type--this corresponds to minimum radii of 200 m to 700 m.  So the A8 cannot be anywhere near as twisty as Interstates were permitted to be, unless exceptions even to the exceptions were granted for some reason.

In Germany, 1942 standards were stricter than in 1933, and I suspect the current standards are even stricter.  The US does have some facilities designed to better than Autobahn standards, such as the New Jersey Turnpike, but these are generally flat-country roads where an objective was to provide much more slack in the design than was called for in minimum standards.

From a Dutch perspective, it's a bit perplexing to see the unlimited speed with the design choices of German Autobahns. Interchanges are designed with much lower design standards in Germany than in the Netherlands, tight curves, 40-50 km/h ramps, no shoulders on ramps or acceleration lanes, two-way traffic with no dividing barrier on ramps, etc. Some of the design standards appear to be stuck in the 1950s. Germany still builds Autobahns brand new with features that were eliminated from Dutch motorway design 50 years ago.

I agree these features--especially the parsimonious provision of speed-change facilities--are hard to understand.

[jakeroot]

Even here in the US, where cloverleafs ruled for so many years, I don't hear about new ones being installed almost ever. In fact, I don't know of any recent installs.

Oklahoma is still building them (are you surprised?). They put one in on the Durant bypass sometime after 2010.

Wow. Not surprised at all. Even more embarrassing for me, since I'm a Choctaw Indian!

[Brandon]

Even here in the US, where cloverleafs ruled for so many years, I don't hear about new ones being installed almost ever. In fact, I don't know of any recent installs.

Oklahoma is still building them (are you surprised?). They put one in on the Durant bypass sometime after 2010.

Wow. Not surprised at all. Even more embarrassing for me, since I'm a Choctaw Indian!

What did you expect from the "CraIG CoUNty" state?

[jakeroot]

Even here in the US, where cloverleafs ruled for so many years, I don't hear about new ones being installed almost ever. In fact, I don't know of any recent installs.

Oklahoma is still building them (are you surprised?). They put one in on the Durant bypass sometime after 2010.

Wow. Not surprised at all. Even more embarrassing for me, since I'm a Choctaw Indian!

What did you expect from the "CraIG CoUNty" state?

Yeah, no shit. Although your comment reminds me that the only "new" one I knew of (until now) was the rebuilt 55/80 interchange outside Joliet. Sure, it was a cloverleaf before, but rebuilding it presented new opportunities for a new configuration. Kind of an IDiOT move, right?

[Brandon]

Even here in the US, where cloverleafs ruled for so many years, I don't hear about new ones being installed almost ever. In fact, I don't know of any recent installs.

Oklahoma is still building them (are you surprised?). They put one in on the Durant bypass sometime after 2010.

Wow. Not surprised at all. Even more embarrassing for me, since I'm a Choctaw Indian!

What did you expect from the "CraIG CoUNty" state?

Yeah, no shit. Although your comment reminds me that the only "new" one I knew of (until now) was the rebuilt 55/80 interchange outside Joliet. Sure, it was a cloverleaf before, but rebuilding it presented new opportunities for a new configuration. Kind of an IDiOT move, right?

Yeah, that's IDOT for you.  Why fix it when we can just make the ramps a bit straighter?  There were those of us arguing that the interchange should have flyovers (even back when it was rebuilt in 2000 or so) from east 80 to north 55 and west 80 to south 55.  Now IDOT, in their infinite wisdom wants a flyover from south 55 to east 80.

[SignBridge]

JNW, you made a reference to Interstate standards in 1944 in your above post. Is that maybe a typo? I'm sure you know the Interstate System wasn't legislated into existence until 1956. But thanks for an otherwise very informative post.

[J N Winkler]

JNW, you made a reference to Interstate standards in 1944 in your above post. Is that maybe a typo? I'm sure you know the Interstate System wasn't legislated into existence until 1956. But thanks for an otherwise very informative post.

You are welcome.  The Interstate standards quoted ultimately come from the 1944 interregional highways report, and the Interstates were first authorized (but not funded) in the Federal-Aid Highway Act of 1944.  What happened in 1956 was agreement as to the ultimate form of the system to be built out and establishment of a dedicated funding stream for its construction.

[SignBridge]

Okay JNW: thanks again. I had not known that history of Interstate planning.

As far as other above posts re: construction features of the Autobahns, I'm surprised to learn from some of the other posters about those antiquated design features of interchanges and Service Areas on the Autobahns. Once again the New Jersey Turnpike seems to do it best.

One area though where the Autobahns shine is in system-wide median barrier protection, with their double guide-rail design. Too many American Interstates (including the NY Thruway) were built in the 1950's and 60's with somewhat wide medians that were thought to provide enough of a buffer to deter crossover accidents. Regrettably that turned out not to be the case and numerous unnecessary fatalities have happened over the years. History has proven that even a narrower median with a Jersey Wall or steel guide rail is the more effective choice.

[Revive 755]

^^
The most perplexing part of the Autobahn, from my perspective, is the use of cloverleafs at so many junctions. I don't know if they're still installed, but I think there might be more in Germany per motorway-lane mile than in the US. Even here in the US, where cloverleafs ruled for so many years, I don't hear about new ones being installed almost ever. In fact, I don't know of any recent installs.

The interchange at the west end of MO 364 at US 40-US 61 in the St. Louis area counts as a recent install, although it would have been a 3/4 with a semi direct ramp for the EB to EB movement  if funding wasn't an issue.  There is a stub at the interchange for this unbuilt ramp.

[jakeroot]

^^
The most perplexing part of the Autobahn, from my perspective, is the use of cloverleafs at so many junctions. I don't know if they're still installed, but I think there might be more in Germany per motorway-lane mile than in the US. Even here in the US, where cloverleafs ruled for so many years, I don't hear about new ones being installed almost ever. In fact, I don't know of any recent installs.

The interchange at the west end of MO 364 at US 40-US 61 in the St. Louis area counts as a recent install, although it would have been a 3/4 with a semi direct ramp for the EB to EB movement  if funding wasn't an issue.  There is a stub at the interchange for this unbuilt ramp.

Damn! I didn't think that was gonna be the 'permanent' layout (didn't realize the flyover was cancelled, for the time being). Last I was in STL, the 364 didn't go that far west (it ended at Pitman Hill Rd), but knowing traffic in the city, I doubt the cloverleaf will wreak havoc anytime soon.



Looking around Germany, I realize there are slightly less cloverleafs than I originally thought. But they are definitely fans of loopy interchanges. There seem to be many 3/4 cloverleafs with one high-speed ramp.

[Chris]

The outside shoulder on the Autobahn is also a bit narrow, in many cases only 2.5 meters (8.2 ft). This, together with many stretches having guardrails almost on the edge of the shoulder, results into broken down trucks standing really close to traffic. Serious crashes where traffic collides with a stopped vehicle are a rather frequent occurrence.

It doesn't help that some drivers park their truck overnight on the shoulder near rest area due to a lack of parking. There is a severe truck parking shortage. They are expanding many rest area with additional truck parking but it isn't enough. The lengthy procedures don't help either.

[SignBridge]

Really, only eight ft. shoulders on the Autobahn? A book I have shows the Autobahn hard-shoulder specification as ten ft. the same as U.S. Interstate shoulders. Maybe on the original East German Autobahns, there were narrower shoulders?  And the New Jersey Turnpike I think has twelve ft. shoulders, a full lane-width. (If anyone knows different, please correct me.)

[bing101]

https://m.youtube.com/watch?v=qg_Y3aRs_nY

Another tour of A9 by DSzumaher.

[DAL764]

Really, only eight ft. shoulders on the Autobahn? A book I have shows the Autobahn hard-shoulder specification as ten ft. the same as U.S. Interstate shoulders. Maybe on the original East German Autobahns, there were narrower shoulders? 

Germany has many different Regelquerschnitte (cross section regulations) for all our roads, and just for the Autobahn alone there are like half a dozen. Those rules were last updated and partially replaced in 2008.

- RQ 31 is the current standard for 2+2 Autobahnen with a shoulder width of 3 meters, replacing the previous RQ29.5 which had the 2.5 meters. RQ28 is quite similar in overall width, though it only applies to Gelbe Autobahnen, as in roads built like the Autobahn but not offially part of the network, similar to  the non-Interstate freeways in the US

RQ36 and RQ43 apply for 6 and 8 lanes, respectively, though those also only feature 2.5 meter shoulders.

It doesn't help that some drivers park their truck overnight on the shoulder near rest area due to a lack of parking. There is a severe truck parking shortage. They are expanding many rest area with additional truck parking but it isn't enough. The lengthy procedures don't help either.

Yeah, the situation is pretty disastrous due to a multitude of issues, most notably the governments being too f'n slow to realise the severity of the issue despite it getting blatantly worse for decades now. More and more cargo is being put on the roads, less and less on the rail, partly because direct rail connections have disappeared, partly because rail is way too expensive/unflexible. Hundreds of smaller parking spots along the Autobahn were also closed over years (small as in could maybe park a dozen trucks only) because the government 'couldn't guarantee the safety of truckers overnighting there', local governments/municipalities have blocked trucks from overnighting in industrial areas (same reason, plus noise), and the fact that Tank&Rast, the company running all the rest areas on the Autobahn, have a near-monopoly and are too busy ripping off tourists needing drinks for their kids after 10pm to focus on actually building new rest areas where they are needed because they wouldn't immediately make a boatload of profit, even if construction licenses have been granted and any objections resolved.

[SignBridge]

Sounds as messed up as our country.........

[bing101]

https://www.youtube.com/watch?v=vXZ-p9Ibsfw


Here is a shot of the A10 under Construction back in May 2018.

[bing101]

https://www.nytimes.com/2019/02/03/world/europe/germany-autobahn-speed-limit.html?fallback=0&recId=1H2nIzmcB5JdAiMkEJTgCBaegYh&locked=0&geoContinent=NA&geoRegion=CA&recAlloc=story&geoCountry=US&blockId=signature-journalism-vi&imp_id=193634662

Here is another take on Autobahns done by NY Times and its over speed limit talks.

[Chris]

Driving in Germany is not as fast as it is often suggested. There are people that drive really fast, but it's not like 'everyone' drives 120 mph.

A study in the state of Brandenburg showed that the average speed on a rural six lane Autobahn is 142 km/h (88 mph) among passenger cars. The V85 was listed at 167 km/h (104 mph). And this was measured on A9 south of Berlin, which is one of the best Autobahns in all of Germany to speed: flat, light traffic and through a forested area.

[jakeroot]

I found this paragraph interesting:

"Germany is terribly regulated, for reasons which have to do with the past, with a fear of uncertainty, a fear of being overwhelmed,"  Mr. Kornblum said. "But then people look for their little spaces of freedom and the autobahn is one of them."

While the lack of speed limit on 70% of the autobahn is, in itself, a freedom, the dangers that come along with it seems to have influenced the behaviour of Germans behind the wheel, and other rules as well. For example, the mental-attention to lane discipline, or rules against breaking down. Here in US, while many states now have left lane laws, too many Americans still don't take high speeds anywhere near as seriously as the Germans, so we screw around a lot more. Whether this has a direct influence on our much higher per-capita road death index, I don't know.

Could Germany lower the limit to 120 or 130? Yes, and I'm sure the Germans would stick to it hard and fast. But, I suspect it may lead to be a bit more road rage than today, as people take too long to pass each, a huge source of road rage here in the US (left lane hogs going 1 mph faster than the other cars, for example).

[Chris]

A real danger in Germany is the number of semi trucks that plow into traffic jams. These result in fatalities almost on a daily basis.

In 2017 there were 409 fatalities on the Autobahn: 101 of those were truck occupants, to compare: in Denmark only 2 fatalities were truck drivers (1% of all fatalities).

[jakeroot]

A real danger in Germany is the number of semi trucks that plow into traffic jams. These result in fatalities almost on a daily basis.

In 2017 there were 409 fatalities on the Autobahn: 101 of those were truck occupants, to compare: in Denmark only 2 fatalities were truck drivers (1% of all fatalities).

Yikes. Perhaps Germany should consider a more robust ATM system? Something to alert drivers of slowdowns ahead.

[Chris]

This is pretty much daily business on the Autobahn. Just in the state of North-Rhine Westphalia there were 197 of such crashes on the Autobahn in 2017, which means it happens every second day in this state alone.

[jakeroot]

Wow.

Any idea what the causes have been? Or at least what the police have said?

Crashes like those in the US are typically blamed on inappropriate speed (such that the driver was unable to stop in time), or inattentive driving (mobile phone usage primarily).

Seattle was having a lot of rear-end truck crashes on I-5 south of Seattle. WSDOT installed a bunch of speed-limit-per-lane signs that decrease prior to a slow down, which are tracked with in-pavement detectors. Hasn't had a massive impact but, ignoring some specious reasoning, it seems to have helped a bit.