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Alon Levy

I don't think the opposition to railroads then, or freeways later, is about that kind of geometry. Pre-industrial roads were linear as well. I recently read a writeup that instead explains it in terms of relationship with nature. Roman and Medieval roads hugged the landscape. Railroads leveled it because they needed to be flat and mostly straight. The same is true of roads for cars: the biggest opposition on grounds of beauty has been to freeways, which also level the terrain or tunnel through it in order to maintain high speeds; the roads from the 1920s, which hug the terrain especially in mountainous areas, are more popular.


It depends on your goal. Roundabouts and Ring Roads (like the one around Paris) are specifically designed to make cars not travel in a straight line. In the case of roundabouts this is done to slow cars down, in the case of ring roads it is to avoid building freeways through the middle of a city (or complement them, as the case may be). So circles are great if you want to purposely slow down travel.

What is frustrating is when you walk diagonally across a public park or plaza every day, but the paths are all curvy and completely ignore the human desire to travel in a straight path. You end up with muddy footpaths all over, because the park designer was in love with swooping curves.


Zefwagner's talk of muddy footpaths reminds me of one of the strongest indications of people's determination to travel in straight lines - the informal but well-trodden footpaths that occur whenever a formal footpath isn't provided along a desire line.

See, for example, this satellite view of the area between Patapsco light rail station and the Cherry Hill neighbourhood of Baltimore: http://goo.gl/maps/Oulmz

Various paths are visible crossing the considerable road and railway options between different parts of the neigbourhood, the light rail station and industrial sites. Zoom out ( http://goo.gl/maps/mI9ii ), and you see the much longer route along curved streets to reach the station designated for the neighbourhood.

This demonstrates well that whatever qualities humans do find in curves and circles, when they have somewhere to be, it becomes a matter of seeking the straightest possible line.

Bruce Nourish

"Roundabouts and Ring Roads ... are specifically designed to make cars not travel in a straight line."

Possibly true for ring roads, not for most roundabouts. If you are driving through an intersection of minimally-congested streets, you'll almost always spend less time getting through an unsignalized roundabout than a signalized intersection or a four-way stop, as you'll never be forced to stop unless there is cross-traffic. It's especially great on a bike, as there's a physical effort penalty to stopping and accelerating. At congested roundabouts, it's probably a wash, but congested roundabouts often end up signalized anyway.

The proliferation of roundabouts in European cities almost certainly does not reflect a judgement about cars, but arises from the simple fact that old cities often have lots of non-right-angular intersections and roundabouts move traffic much better through them; also, over time, drivers have also become accustomed to them, so traffic engineering practice has tended to favor them, rather than regard them as some dubious exotic import.

Similarly with ring roads, I think they arise largely from practicalities. The straight lines of the railroads came to a dead halt at the edge of the old city of Paris until the RER connected them; they still mostly do in London, although Thameslink and Crossrail have started to connect them. This is because even back then, major construction in the heart of an incredibly dense metropolis was unaffordable and impractical; only modern tunneling and the massive bonding capacity of the contemporary nation-state can make it happen.

To Jarrett's point, I think there's something here, and I applaud the effort, but I'm a little reluctant to fall down the semiotic rabbit hole of comparing switches and aboriginal paintings and fortresses.

I think the answer is a little simpler. In general, many of the well-meaning, good people who vote, advocate or campaign for a given cause X, do not have a sufficient grasp of the underlying facts and arguments about the pros and cons of X to construct an argument for it that can hold up under serious analytic debate, of the kind that engineer-types like to engage in. Warm fuzzy ideas of identity and community and inclusion and cycles form something of a substitute; but a substitute that's very effective at making a lot of people feel just good enough to sign an online petition or cast a vote.

Sadly, even if my suggestion is true, I have no clue how to use it to advance the agenda of building transit that doesn't suck, or reforming our transit systems to suck less.

John Smith

Ancient Man first moved heavy objects by using a straight stick as a simple, single lever. To make moving things easier, he wanted more levers, so he joined two sticks into a simple cross-shape, joined another pair into another cross, and joined the two with what we would call an axle. By adding more ‘spokes’ to his crosses, he could make the job smoother and easier; by joining together the outer parts of the spoke, he had a wheel. This suggests to me that the ‘circle’ is nothing more than an artificial construct describing the outer points of an infinite number of bisecting straight lines.

Here in North East England, there are many examples of Roman forts and towns, laid out in rectangular ‘playing card’ style. Towns tend to expand from a centre linearly, like spokes on a wheel; and if you note the outer limits of the linear expansion and join them together, you will (unless there’s a natural boundary such as a river) draw a circle – another artificial construct, but one that tends to become the city limits.

We use circles on maps to define areas, to make them easier for our simple minds to comprehend where things are. But underlying the circle is the dominant straight line.

And a straight line is not called a ‘rule’ for nothing!


Roman and Medieval roads hugged the landscape. Railroads leveled it because they needed to be flat and mostly straight.

That may be true in general, but there are certainly exceptions, for example: "To this day the Via Appia contains the longest stretch of straight road in Europe"

David Crossley

No, wait, the green strategy, at it's greenest, is about straight lines connecting circles. The nodes of a transit network are circles because the only way to express distance from the center (the station) that people will walk is a radius around that point. You're absolutely right that all travel should be in straight lines, and people walking across grass in campuses prove that. So the question in this is whether walking and biking lanes should radiate outward from the station, as some do in Washington, or have a grid imposed. But the green goal should be straight travel line at least among places.


The inherent form of natural systems is not he circle but the fractal. We simplify many natural systems into circles to reduce complexity. If we view natural systems through the fractal lens then our thinking would align with city systems. After all, if we want to consider a transit system as a whole, our thinking turns toward fractals.


Roman roads did not "hug the landscape" - they were dead straight for as long as possible to cut the distance troops had to march.

You might be thinking of the canals which - to reduce the need for locks - followed contours.

Steam engines work better on grades of 2% or less, but the lines were never straight except in exceptional locations like Australia's Nullabor Plain. Railway lines through the Rockies were both steep and twisty.
Modern High Speed Trains powered by electricity can cope with much steeper grades, but need gentler curves for human comfort - unless they have working tilt mechanisms.

Even when we have the technology to build straight lines, economics usually dictates otherwise - see for example the curves built into the Canada Line in Vancouver to get it around a nasty bit of really hard granite under Queen Elizabeth Park


"Transportation planners -- including those of us who value the goal of a more durable civilization -- are in the business of trying to convince circle-lovers of the value of straight lines."

Ah! But what are your beloved frequent bus grids if not a large collection of circles? Yes, as you later say, each individual wants to go straight from place A to place B. (You also seem to say later that only tourists then want to return, circularly, to their original starting place; I must say that I myself prefer to also eventually return home, and sometimes even to stop at a third location on the way, but perhaps I am perverse in this way?) However, I seem to remember you frequently, and correctly, arguing against any particular effort to actually provide that individual with an equally individual way to take that straight route; e.g. no self-driven or automated cars, multiple overlapping bus routes from everywhere to everywhere, on-demand routing or the like. Yes, Jarrett, it seems you too are a circle lover, no matter how hard you fight it. :)

(That aside, does the problem you're apparently out to oppose here really exist? If it does, is identifying and fighting it more beneficial than simply describing your ideas and findings on their own merits? I have to say you finally lost me completely up above when you started relating this to the symbols on (some) computer buttons. Like, wow man, far out!)


I don't see the circle and the straight line as being incompatible, at least in the context you describe -- they are arguably closely related. You note that medieval fortifications developed in circular patterns because it maximizes area and minimizes perimeter, but the other thing a circular form does is minimize the distance from all points to the centre. That's the same as today's catchment area for a transit stop (or walking distance to neighbourhood store, or whatever other facility). Radius is the connection between straight line and circle.


Jarrett: it's not the line that you should emphasize with the green folks. It's the network. The network creates the enclosure that the system people need to understand what's going on.

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