Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 



Forgot your password?
typodupeerror
×
AI Transportation

Daimler Tests a Self-Driving Truck On the Autobahn 130

Engadget reports that Daimler has tested an autonomous truck in one environment guaranteed to put stress on any car: the German Autobahn. While the Mercedes Actros truck was guided with a mix of "radar, a stereo camera array and off-the-shelf systems like adaptive cruise control," there was a human crew on hand, too, just in case. From the article: This doesn't mean you'll see fleets of robotic trucks in the near future. Daimler had to get permission for this run, and the law (whether European or otherwise) still isn't equipped to permit regular autonomous driving of any sort, let alone for giant cargo haulers. Still, this could make a better case for approving some form of self-driving transportation.
This discussion has been archived. No new comments can be posted.

Daimler Tests a Self-Driving Truck On the Autobahn

Comments Filter:
  • About damn time (Score:5, Insightful)

    by Z34107 ( 925136 ) on Sunday October 04, 2015 @08:14PM (#50658791)

    The article's a bit short on details, but this is where I expect autonomous driving to take off first--long-haul trucking. Controlled-access highways present fewer complications like pedestrians, four-way stops, and the like, and I imagine automating that would take care of 80% of the driving. Even if you still needed a human driver to reel 'er in at the warehouse gates or even the city limits, it still strikes me as a huge improvement.

    Laws and liability are going to be the biggest limiting factor to commercial deployment, especially if they boil down to "a human must be ready to intervene at any time," but I think there are fudges around that. You could have one human operator in a remote control center "driving" multiple trucks, kind of like a cross between drone pilot and remote ICU monitoring.

    Not that even a human sitting in the seat with hands on the wheel would be likely to intervene effectively should something go wrong after eight hours of idle monotony. But, having a human somewhere supervising in some capacity would soothe the more irrational fears that also serve as part of the reason we still keep human pilots flying planes, while still yielding the benefits that come with automation--self-driving trucks are much less compelling if each one still needs a full-time human driver to comply with laws.

    • Re:About damn time (Score:5, Insightful)

      by phantomfive ( 622387 ) on Sunday October 04, 2015 @08:42PM (#50658883) Journal

      The article's a bit short on details, but this is where I expect autonomous driving to take off first--long-haul trucking

      Our trains aren't autonomous yet, which seems like a much easier problem to solve.

      • Re: (Score:2, Informative)

        by Anonymous Coward

        The article's a bit short on details, but this is where I expect autonomous driving to take off first--long-haul trucking

        Our trains aren't autonomous yet, which seems like a much easier problem to solve.

        "Our" trains for the most part are, the engineer just sits there to make people feel good.

        Which country are you talking about?

        • by Anonymous Coward

          One of the fun things is signalling. At normal freight speeds humans are a perfectly fine solution. They can recognise non-standard signage easily and handle weird corner cases without specific instruction.

          But at high speed (200mph) humans are too slow, so actually a human driving the train is inherently unsafe. We have to get rid of the human-readable signs, they pass too quickly to read properly anyway. Where we're obliged to put a human in the loop, we give them a computerised speed target and a brake /

        • There are plenty of automated rail systems around, mostly in the light commuter sphere. Many of them still have a human, if only to hit emergency stop if needed and work the doors (people like to take chances with closing ones).

      • Re:About damn time (Score:5, Interesting)

        by Z34107 ( 925136 ) on Sunday October 04, 2015 @09:09PM (#50658947)

        It's harder than you're probably giving it credit for, especially for miles-long freight trains, where a hill can mean one segment of the train is accelerating while another is decelerating. We're just about there, though, insofar as we have software that automatically drives throttle, brakes, and other controls. Link [economist.com]:

        Norfolk Southern, an American rail operator, now pulls roughly one-sixth of its freight using locomotives equipped with "route optimisation" software. By crunching numbers on a train's weight distribution and a route's curves, grades and speed limits, the software, called Leader, can instruct operators on optimum accelerating and braking to minimise fuel costs. Installing the software and linking it wirelessly to back-office computers is expensive, says Coleman Lawrence, head of the company's 4,000-strong locomotive fleet. But the software cuts costs dramatically, reducing fuel consumption by about 5%. That is a big deal for a firm that spent $1.6 billion on diesel in 2012. Mr Lawrence reckons that by 2016 Norfolk Southern may be pulling half its freight with Leader-upgraded locomotives. A competing system sold by GE, Trip Optimizer, goes further and operates the throttle and brakes automatically.

        • Installing the software and linking it wirelessly to back-office computers is expensive,

          If you're relying on the ability to always be wirelessly in contact with a central server, then this project is a fail (maybe they aren't relying on that, though, it's not clear).

      • Re: (Score:3, Interesting)

        by Anonymous Coward

        It is about cost.

        Lets say there are 100k drivers for a train. They are about a median of 50k each. Or about 5 billion a year in cost.

        There are ~1.7 million drivers of trucks with an median of ~40k each. Or about 68 billion a year. With another 1.3 billion doing short load delivery (about 32 billion)

        Trains are actually fairly much automated at this point. With the driver being the final say. Their job is mostly inspection and kicking kids off.

        Trucks are not even close in cost and cost 12x as much.

        To un

        • To underestimate how much automated trucks will inside out the industry is not to really understand it. This will wildy reduce accidents. The number of people injured by trains is tiny compared to the 80-100k per year with trucks (about 4-5k per year).

          Automating trucks is great in theory: the difficulty is implementing it in practice.
          That's why I brought up the train example: automating freight trains is an easier task, by several orders of magnitude, and yet it hasn't been done yet. We still keep a driver on.

          • Re:About damn time (Score:5, Interesting)

            by TWX ( 665546 ) on Sunday October 04, 2015 @11:03PM (#50659289)

            To underestimate how much automated trucks will inside out the industry is not to really understand it. This will wildy reduce accidents. The number of people injured by trains is tiny compared to the 80-100k per year with trucks (about 4-5k per year).

            Automating trucks is great in theory: the difficulty is implementing it in practice. That's why I brought up the train example: automating freight trains is an easier task, by several orders of magnitude, and yet it hasn't been done yet. We still keep a driver on.

            Couple of things...

            Depending on who owns the rail infrastructure it might be difficult to get the owner to actually make the improvements that are necessary to leave the current paradigm for an autonomous one. That means that there really could be times when something has to be done manually on the rail line, or when the experienced engineer needs to change the speed or other behavior of the train to account for local conditions.

            Trains, believe it or not, are allowed to operate with severe deficiencies in key systems, like brakes. That's right, there are instances when of those four locomotives pulling the train, two of them have full brake failures. I don't know what the exact ratio is, but it's rather unsettling given the mass involved, that they do not have to be in tip-top shape.

            There are collisions that do not mandate that a train stop. If a train hits animal life or debris on the tracks there isn't necessarily a need to stop the train. If a train hits a person or a car or some other condition there might be a good reason to stop the train. It may be difficult to tell, in a simple automated way, what the train has struck given the mass difference of the train versus anything that it strikes short of another train.

            Per given unit of freight mass being delivered, having an engineer or two on-board is still not very expensive. Factor the rest of the considerations listed and for the moment it makes sense to keep an engineer or crew onboard. Fix those, and it might be cost-effective to be automated.

            • by Roest ( 1556855 )

              but it's rather unsettling given the mass involved,

              That's no problem at all. If you knew how train brakes work, you'd know that every car of the train is braking itself.

              • by TWX ( 665546 )
                Tell that to the people that used to live at the bottom of the Cajon Pass....
          • The cost of the driver of a train is neglectable compared to the 20 or more carriges in a train which compare to one or two truck loads.

            Automated trains are used on high speed tracks and subways.

        • Trains still have to deal with manual sidings, manual hooking / unhooking of cars + all the of safety stuff that needs some one on site.

        • "To underestimate how much automated trucks will inside out the industry is not to really understand it."

          There are estimated to be _at least_ 80-160 million people worldwide involved in the transportation industry whose jobs will be directly affected by vehicle automation (ie, "drivers"), without the knock on effects of the industries that support or depend on those people (trainers, and even stuff like roadside services)

          Automating driving on a freeway/autobahn is easy. It's the low-hanging fruit (Look at t

      • by Anonymous Coward

        Some countries already have fully automated metro systems, Australia is building one now.

      • Planes are more 'autonomous' than trains. Personally, I think 'automated' is a better word.

        • Yeah, but planes typically still have two people driving; trained, alert, and ready to take over if something goes wrong.
      • Re:About damn time (Score:5, Informative)

        by Tom ( 822 ) on Monday October 05, 2015 @02:07AM (#50659803) Homepage Journal

        According to WP [wikipedia.org], there are a number of fully autonomous metro lines in the world, and a longer list where there's a human basically just to intervene in case of emergencies.

    • remote control has to meny points of fail that can cut the link.

      • by fisted ( 2295862 )

        Implement on the train:

        if (link_down())
            halt();

        Implement at the control station:
        if (link_down())
            foreach (other_trains_on_that_track())
                signal_halt();

        • by Joe_Dragon ( 2206452 ) on Sunday October 04, 2015 @11:47PM (#50659479)

          So All I need a cell jamer and I can DDOS you full rail line?

          • by fisted ( 2295862 )

            No, you cannot DDOS me full rail line.

            What you can do, is DoS a partial rail line.
            Much like all you need is a laser pointer and you can DoS a full airport, or a few rocks and you can DoS a reasonable piece of a motorway.

        • If a train is stopped in a segment the segment behind him will stay blocked. It is only released when the train has left its segment. At least that is how railways are operated in most parts of Europe.

          Anyway, your algorithm would cause a major collapse and of the railway system. You would rather built it with some decision support. However, high speed trains use multiple ways to communicate position and speed. And they know how fast they can go at any segment of the tracks.

    • Re:About damn time (Score:5, Interesting)

      by climb_no_fear ( 572210 ) on Monday October 05, 2015 @12:42AM (#50659633)
      Except that in Germany, the country is criss-crossed by train lines.

      My little village has a station of its own, served several times a day. I can (and have) gotten in the train and with only one transfer, gone to Berlin, Paris and London. What you say is probably true in the US but not here.

      Also, when you say controlled-access highways, please remember, this is the Autobahn, and yes, people do drive 230 kmh (trucks are limited to 100). Most people would like to have fewer trucks, simply because of the speed differential.
    • by rioki ( 1328185 )

      I once drove a car that was fitted with adaptive cruise control and lane assist. I very rarely needed to do anything, just watch traffic and be ready when the systems disengaged or misbehaved. This system is basically a beefed up version of the combination of the two.

      This feels quite like the autopilot on an airplane. You focus on the big picture tasks and don't concentrate on the minute details of flying the airplane. The result is that the pilot is more alert over a longer period of time.

      I can see these t

    • There's another reason that autonomous driving is more likely to happen sooner in trucks: "Real Estate" and "space"

      As in "Real estate to hang the sensors from" and "Space to put the processing hardware", with weight not being as important a consideration either.

      Sticking all this stuff in cars is still problematic, even if Delphi has managed to get the back end down from a trunkful of kit to 1/4 of that size for a mostly autonomous machine.

  • by Anonymous Coward on Sunday October 04, 2015 @08:14PM (#50658793)

    People on the autobahn are generally courteous, signal when changing lanes and so on. I guess you'd have to be at such speeds, but it's also part of the German national character. Furthermore, it's a highway so everyone is driving fast and the velocity differences, which cause most of the danger, are actually rather low most of the time. I think the highway may possibly be the safest and easiest environment for automated driving.

    • by _merlin ( 160982 ) on Sunday October 04, 2015 @09:43PM (#50659031) Homepage Journal

      Yeah, I have to agree. Autobahn has very strict rules about not passing someone to their right, and people actually follow them. People are also generally courteous about getting up to speed before entering, leaving gaps for people to enter, getting out of the left lane for people wanting to pass, indicating for lane changes and exits, etc. Automating driving on an Australian freeway would be far more challenging, and even that would be easy compared to an intercity road in Vietnam.

      • by Kjella ( 173770 )

        Yeah, I have to agree. Autobahn has very strict rules about not passing someone to their right, and people actually follow them.

        Because it's the slower car's job to get out of the left lane so if there's space and they're impatient they'll be sure to blink or honk to get you out of their way. I guess it's a cultural thing, if it's the faster car's job has to find a free lane to pass that system works too. Mixing the systems don't though, if both switch lanes at the same time the result could easily be a crash. And then there's the systems where lanes are fluid or non-existing including but not limited to opposing lanes, if it fits d

        • by KGIII ( 973947 )

          The Autobahn is something Germany got very right. My career was traffic modeling and I'm impressed with the Autobahn. I went a few years back just to drive on it as I'd not experienced it personally and felt that I must. I'd considered shipping one of my own vehicles over (I'd have gone with my Saab - an older 900S Turbo) but I opted to, instead, rent a beefy Audi for the trek.

          There's also the cultural thing - the system was very orderly and, while I had no dealings of this nature, I guess those who violate

          • I hope you have better luck with your BMW then my son had with his. The first year he owned it the dealer had it more than he did. After a second year the brakes needed complete replacement. When the light came on showing a little car up on jacks he limped it into a Ford dealership and left in a Ford Focus. He is a lawyer with a German multinational but he said he couldn't afford gas and repairs on that car.
            • by KGIII ( 973947 )

              I own two, one of which is 'bespoke' and I just got it a few months back. I had another, which is where I fell in love with them, that is a 1995 740Li. My son still drives it today and he can easily afford another vehicle.

              However, yes, they're very expensive to maintain. They are not cheap to run, not even remotely. Fuel consumption varies with use, quite a bit too. If I drive like I'm sane then I get 28 MPG or so. I can easily get that down to the 18 MPG range by changing my driving style. If I'm really ge

              • Where I live having a collection either means you have several old cars up on blocks in your front yard or a five acre barn lot covered with rows of parked tractors and harvest trucks. My wife made me get rid of the first and I lost the other to the bank. The only things I have now are my 1998 Silverado and my wife's 2000 Mercury Grand Marquis.

                It is humbling to lose all your stuff but after 20 years I have got used to it. My children are doing well so I can't complain.

                • by KGIII ( 973947 )

                  I do have a few that haven't yet been able to make it to a body shop and be restored. Those are project cars and I generally only keep a few around to avoid the clutter. I just had an old GMC tow truck finished earlier this year. It's as awesome as one might imagine. :D

                  Believe it or not, I kind of want a firetruck. Technically I want an Oshkosh but the model I want is not something I can buy as a civilian. So, I'll settle for a firetruck the next time a base closes. They're surprisingly cheap that way but t

    • Having driven on the autobahn it's probably the easiest place to try something like this. Everyone there already moves like robots. It's like some lawmakers figured out an "API" for how to communicate between vehicles.

      I want to see it done around Chicago where it's "surprise, I'm coming into your lane".

      • by cyn1c77 ( 928549 )

        Having driven on the autobahn it's probably the easiest place to try something like this. Everyone there already moves like robots. It's like some lawmakers figured out an "API" for how to communicate between vehicles.

        I want to see it done around Chicago where it's "surprise, I'm coming into your lane".

        Or Boston, where the only way to change lanes is to pretend that you're driving drunk, so that everyone will back off!

      • They better be able to go way over the limit for it to work in Chicago or they will stuck at 55 while others blow them away.

      • The BIG difference is that you have to take dozens of driving lessons, both theory and practice before even allowed to register for the driving test that typically last 45 minutes and usually includes highway driving. Not like the 10 minute test in the US driving around the block where the DMV is. The huge difference is that European drivers are just way better trained, something the US direly needs, especially to get the motor vehicle fatalities down.
    • by TonyJohn ( 69266 )

      People on the autobahn are generally courteous, signal when changing lanes and so on. I guess you'd have to be at such speeds, but it's also part of the German national character. Furthermore, it's a highway so everyone is driving fast and the velocity differences, which cause most of the danger, are actually rather low most of the time. I think the highway may possibly be the safest and easiest environment for automated driving.

      I agree that the Autobahn is a well-ordered place to drive but, where there is no speed limit, there are some large velocity differentials: the car in the outside lane may be doing 210kmh or more, but the lorry in the inside is probably doing about half that. That's a little alarming when someone pulls out to overtake the lorry on a two lane carriageway.
      J

      • by fisted ( 2295862 )

        Most unrestricted parts are at least three lanes, presumably for exactly this reason.
        That said, trucks are limited to 90 km/h no matter what, and, even on unrestricted parts, seeing someone do 200+ km/h is exceedingly rare. It's fun, but much too expensive to do it on a regular basis.

    • by Tom ( 822 )

      Yes, it's pretty much a national custom. Also, Germany has extensive driving school with compulsory minimum hours, and driving instructors teach you strongly to signal. You can actually fail the driving test if you don't signal.

      However, I disagree on the velocity differences. That depends very much on where you are driving. Some parts of the Autobahn have a 120 km/h speed limit and there you basically have two speeds: 80 km/h for the right lane, mostly filled with trucks, and 120 km/h on the 2nd and 3rd lan

      • by fisted ( 2295862 )

        You will actually fail the driving test if you don't signal.

        Some parts of the Autobahn have a 120 km/h speed limit and there you basically have two speeds: 80 km/h for the right lane, mostly filled with trucks, and 120 km/h on the 2nd and 3rd lanes.

        In reality, on sections restricted to 120, you'll have trucks going 90 on the right lane, most people averaging 120-130 on the middle lane, and some doing 150 on the left lane.

        no speed limit [..] means you are driving 180 on the middle lane, passing a truck doing 80 on the right lane, and someone going 280 passes you on the left lane.

        Hypothetical much?
        On unrestricted parts, you'll stil lhave the trucks go 90 on the right lane, most people averaging 120-130 on the middle lane, and the occasional speeder doing 150 and upwards on the left lane. People that do 180+ generally use the left lane, even when the middle lane is free (which makes sense to me, even if it is

        • by Tom ( 822 )

          No, it's perfectly legal to use the left lane, as long as you occasionally pass people on the middle lane.

          Now, as for people doing 280+, I have yet to see one.

          You're looking at one. Not very often, but an M3 will get you to 290. There's the occasional supercar as well that I've seen pass me when I was doing 220 or 240.

          It's not very often that you have to make way when you're doing over 200, but it happens.

          In reality, on sections restricted to 120, you'll have trucks going 90 on the right lane, most people averaging 120-130 on the middle lane, and some doing 150 on the left lane.

          True, it's not quite as simple as I made it, but in general, people drive speed limit +10.

  • by zenlessyank ( 748553 ) on Sunday October 04, 2015 @08:29PM (#50658845)
    German self driving tanks sound like more fun. Maybe some armored drones and, and LASERS!!!!!!
  • Highways are very simple, continuous lanes, very little complication, city roads are a whole different story.

    Non-story.

    • by Kjella ( 173770 )

      Highways are very simple, continuous lanes, very little complication, city roads are a whole different story. Non-story.

      On the other hand... if you have a bunch of depots in conjunction with the Autobahn, you just pick up/drop off goods at the one closest to you and automated trucks bring it to the depot closest to the destination that could be a much quicker road to implementation than dealing with inner city traffic. Also much easier to map out, assuming you need that. The point is to start somewhere.

      • Or you just can use rail.

  • Just wait (Score:2, Insightful)

    Automated trucks without any drivers? Sounds like a hijackers dream!

    • How do you hijack a truck that's constantly remotely monitored and controllable?

      • areas with poor cell coverage.

        the lag and small caps on satellite broadband make it not a good choice for this even more so when cell broadband has lower costs and bigger caps.

      • by mjwx ( 966435 )

        How do you hijack a truck that's constantly remotely monitored and controllable?

        Feed them false data?

        But why bother, all you need to do is jam the signal so they cant send new commands.

        If all you want is the cargo, pick somewhere where there wont be any responders for at leas half an hour (not like there will be many spots like this), order the truck to stop (it will have half a dozen safety protocols designed to do this, you'll just have to trip one and chances are you wont need to have the authority to issue commands to the truck to do is).

        So the theft is simple:
        1) Trick th

        • and the cops will probably be en-route, since the truck made an emergency stop and lost communications. It could have hit someone.

          You'll also be recorded on the various cameras the truck uses to drive.

          You've got to get in to the locked trailer before the cops get there too.

    • Re:Just wait (Score:4, Insightful)

      by MobileTatsu-NJG ( 946591 ) on Sunday October 04, 2015 @10:06PM (#50659109)

      What would a driver be able to do about it?

    • by Tom ( 822 )

      And you would hijack such a truck how, exactly? Get on board and threaten the computer with counting?

      • Pull up next to the truck on an empty road, smash the cab window, get inside and hit the e-stop. No need to worry about a driver calling the cops or pulling a gun. Empty the contents and be gone. Hell get 3 junk cars like others suggested and box it in.

        • by Tom ( 822 )

          Firstly, in Germany the driver will not pull a gun on you anyway, because we're not maniacs armed to the teeth, we have strict gun laws, and very few shooting sprees.

          Secondly, what makes you think the truck won't call the cops (or at least a control center) when you smash the cab window and hit some kind of emergency stop? Or when the freight doors are opened at an unauthorized location?
          What makes you think there won't be a camera or three, streaming pictures of your face to the control center?

          Your scenario

          • Cops are going to put a very low priority on automated calls from trucks. I'm talking about in the USA where nearly everything is transported by trucks.

  • by Jim Sadler ( 3430529 ) on Monday October 05, 2015 @12:14AM (#50659549)
    Think about it. One tractor trailer driver can easily be paid 60K per year and he must get food and shelter allowances as well. The law limits his hours in the cab so unless he is breaking the law that truck will sit still at least 12 hours a day. On the other hand a machine driving the truck requires zero rest so that truck can keep rolling 24/7 with brief stops for fueling. That means operation of a truck will be reduced in cost by 60% or greater. Further the customers will get much faster delivery of their orders. Trucking companies will want this like you won't believe. Taxis will also be automated and we will probably see Uber cars automated as well. The cost of owning such a vehicle will be far lower as the vehicle can stay in constant use. So you own the vehicle and it is out earning you money every minute you are not in your car. This means that we can reduce the actual number of cars on the road vastly. Further your automated car can drop your kids off at school and then go to the grocery store and have it loaded by the bag boy and the car brings your order home. Amazon is about to start a delivery service such that products from any store can be delivered to your home. One side effect is that hundreds of thousands of jobs are about to vanish because of this technology.
    • "The law limits his hours in the cab so unless he is breaking the law that truck will sit still at least 12 hours a day."

      For an owner-driver perhaps. If there is a large enough network of trucks (or depots being driven between) then multiple shifts can keep a large truck running almost continuously. It's for this reason that large ones (44 tonnes) tend to have relatively "short" lives - in 4 years they may put 2million km on the clock.

      Once "drivers" are mostly "minders", the operating hours of trucks are li

  • If it drives better than the average Eastern European drunk that is the typical 'driver' for these vehicles nowadays, it's a success.
    • Indeed. However, I am not sure if this is limited to any nationality. Many cheat about breaks they have to take, which results in their inability to stay on their lane.

      One more cause for me to chose trains.

  • clueless author (Score:5, Informative)

    by Tom ( 822 ) on Monday October 05, 2015 @02:05AM (#50659793) Homepage Journal

    one environment guaranteed to put stress on any car: the German Autobahn

    Uh, no?

    Have you ever actually driven on the German Autobahn? It is probably the most simple environment for an autonomous car, because absolutely everything is very clearly defined and built to standards. You have very reliable road quality, width, signaling. No traffic lights, roundabouts or intersections. Very few traffic rules (basically speed limit and whether or not trucks are allowed to overtake on this stretch). Construction sites are about the only tricky spots you will ever encounter. Even incoming and exiting traffic is very simple to handle, because there is one and only one way in which it will ever happen.

    If I were to write autonomous driving software, I would start with the Autobahn, and then go to more complicated road systems later.

    For trucks, even speed is trivial. The general high speed of trucks is 80 km/h, so if you are a truck you stay on the right lane and stick to that speed and that's it.

    Left-lane driving on the Autobahn is more interesting, especially for foreigners (you think you're going crazy fast in your rental car at 190 km/h (about 120 mph), and there's this BMW behind you signaling to get your slow ass out of the way). But we're talking about trucks here.

    • by KGIII ( 973947 )

      Just a point of clarification... Professionally we tend to refer to those 'on/off ramps' as 'interchanges.' However, some will (and I guess they could, it's just not specific enough in my opinion) call those intersections as they do, indeed, intersect with the highway. However, interchanges are typically referring to limited access highways and have some subsets. While a bit rare, it's not entirely unheard of to see interchanges referred to as intersections - even in some documentation.

      • by Tom ( 822 )

        No, I meant intersections. The Autobahn doesn't have them. Some highway systems in other countries do have traffic lights, intersections, crossings, roundabouts. The German Autobahn does not.

        • by KGIII ( 973947 )

          Oh I know what you mean (I'm pretty sure - I've made a special trip just to drive on the autobahn and experience it in person) but I wanted to make sure that people knew the difference. One could, reasonably but terribly broadly, say that an on-ramp is an intersection (and sometimes they do). However, we usually refer to those as interchanges.

          A road without any intersections would have absolutely no way to get on or off it - at all, as it must intersect with others in order to access it. Using that definiti

      • by neminem ( 561346 )

        Funny - I wouldn't call them "intersections", but I wouldn't call them "interchanges", either. To me, an "intersection" is where two non-freeways meet, and an interchange is where two *freeways* meet. I wouldn't call the intersection of a freeway and a non-freeway *either* of those terms (yes, it is certainly an intersection by the geometric definition, but that doesn't make it "an intersection" colloquially in the context of driving.) I would only ever call it an on-ramp, off-ramp, or if it's both next to

        • by KGIII ( 973947 )

          On paper they're usually called an interchange though sometimes they're called intersections. Your local highway department will have the drawings and associated documentation (and perhaps a study) available if you want to review them.

"The following is not for the weak of heart or Fundamentalists." -- Dave Barry

Working...