Street Layout

[saltandsauce 0]

as we can all see most new developments have little cul de sacs and dead ends

lets see which is more popular

dead worm streets are notorious for getting lost in especially if they are littered everywhere and the house your looking for is at the end of one.

new neighbourhoods also have curved street to slow traffic down apparently it also has this weird effect of you looking down the street all the time its hard to look straight ahead constantly.

the streets are very wide.

old neighbourhoods usually have the rigid grid iron pattern this is especially prevelant throughout the USA .

the streets are usually narrow with cars parallel parking on the side reducing them to one way streets parking is a problem.

there are lots of junctions so being lost is still a problem but you don't have to turn back. people drag racing down streets can be a problem which the straightforwardness can induce.

basically do you like dead worm streets or grid iron or something else?

[super_monkey 0]

uhhhh... so what am I suppost to say??

[ilikehotdogsalot 307]

Please use commas and periods, it's really hard to interpret what you're saying.

[Duke87 1,070]

People like living in dead end streets because it means that no one who isn't destined for a house on that street will be driving there. Thus, traffic is negligible and the street is quiet, making living on it more pleasant.

But it's a double edged sword. Because a street not going through reduces access to the people who live on it as well. In an area with a lot of dead ends and cul-de-sacs, one may have to take a rather circuitous route to get between two points which are relatively close together. When the idea of suburban developments like this was first conceived, that was generally regarded as not being an issue since they were designed with cars as the sole mode of transportation in mind. That unnecessarily long route isn't so much of a problem if you're driving, but it is a big problem if you're walking.

Even with driving, though, there are issues other than longer trips. By funneling all through traffic onto major roads and keeping it off of side streets, you can cause a lot of congestion on those major roads quite easily. Plus, the lack of redundancy means that when an accident or construction blocks all or part of one of those main roads, it hurts a lot more and if it happens in the wrong place it may even effectively trap people by cutting off the only route by which they can drive out of their area. Also, dead end streets mean dead end utility lines- and with water distribution systems, that's a very undesirable condition both because of the redundancy issue already mentioned (shutting off a major pipe then means shutting off a huge portion of the system) and due to water quality concerns- water distribution systems are designed with loops because you want the water to keep moving. If it becomes stagnant, it allows bacteria to grow much more easily. And if nobody on that dead end street is using water at a given point in time, water in the pipe will be completely still.

You mention narrow streets being an issue, but  grids and narrow streets don't automatically go hand in hand. You can easily design a grid with wider streets. The reason you see narrow streets in cities has nothing to do with them being in a grid (Europe almost never uses grids and their cities have some very narrow streets) and everything to do with their age (not as much traffic in cities in the old days).

The thing you said that realy gets me, though, is "there are lots of junctions so being lost is still a problem". Tell me honestly which of these street systems you think would be easier to navigate:

If you answered "the one on the right", your personal flavor of spacial intelligence is highly unusual.

 

[Joetropian1 1]

LEFT! LEFT!

JT1

[hamsterTK 93]

It seems like many places use varying kinds of hybrids possibly to save money on utilities, as duke said it costs more to build things so curvy like that.

I think for pedestrian connectivity is sometimes important to think about exactly what routes people would be taking on foot, usually to parks, kids to school, and then maybe not a full grid but rather some kind of hybrid would come into play.

[david1314 44]

It seems to be a question of roads to nowhere (this would be your suburban maze neighborhoods), the road to the north (this would be a rigid grid), and a road to where you're going (this would be an organic Washington DC/London etc. styled city).

Unless you like wasting gas and braving traffic, roads to where you're going are probably the most useful.

[Nardo69 51]

Actually IMHO the truth lies in between the road "grids" of Duke87.

The left grid is perfect for a higher network of highways, avenues and roads for easily distributing local traffic and let transit traffic run through the network without too much loss of time and therefor Gas. It is also perfect for a pedestrian network as pedestrians are very sensitive to deviation.

The right network is perfect to connect the houses within the loops of the left network i.e higher network. It connects all the small places to the higher network without giving transit traffic unwanted shortcuts through the small streets.

[GMT 389]

left is easier to navigate, no question, but the right one is the far better in terms of visual quality (not just from above), and living quality, if it's a residential area, because it's more likely to be suburbian (like it's around NYC on the northern jersey side).

Not to mention that it's not that much harder to navigate the right one aswell, you have the main road, 1st level subroads and 2nd level subroads with the dead-ends...

maybe it's that I'm used to such a layout for a real block-layout isn't usual where I live...

[Duke87 1,070]

Originally posted by: Nardo69

The left grid is perfect for a higher network of highways, avenues and roads for easily distributing local traffic and let transit traffic run through the network without too much loss of time and therefor Gas. It is also perfect for a pedestrian network as pedestrians are very sensitive to deviation.

The right network is perfect to connect the houses within the loops of the left network i.e higher network. It connects all the small places to the higher network without giving transit traffic unwanted shortcuts through the small streets.quote>

But, see, this is exactly what I was criticizing. Relegating all traffic to main roads causes congestion issues and reliability issues.

Obviously, a grid isn't all that ideal in a suburban or rural setting, but in those cases the issue is not so much that the streets aren't straight as it is that they don't go through. I despise unnecessary dead ends since they impede efficient flow of traffic (particularly for pedestrians and cyclists but also for cars) and pose an issue for utility function. Going back to the previous example:

(assume that any road which doesn't have a dot at the end continues off the edge of the map).

In this case, the network on the left, while it is not an organized grid, is still a huge improvement over the network on the right- because it makes all streets through streets and has more four way intersections, thus reducing the number of turns you'll have to make to get from one place to another, and providing more alternate routes to use in case one gets blocked. There's no place which there's only one way into and out of.

[Namesys 3]

I weren't in USA to taste those endless grid systems, but i'm sure i'd 10 times easier get lost in those grids where "everything seems the same" and you are in a maze or something like that. The ones on the right have more unusual features and road curves so you easier find yourself on a map and where to go. I don't know it's just a guess.

Duke87, dead ends are never used in the centres of the cities. At least not in ones I know. In europe i think the real road system is the left on your second picture comparison.

[david1314 44]

The grid is a failed system. It does not offer the shortest route, the least traffic, the most efficient speeds, the fewest stops, or any compromise thereof. It mindlessly crosses roads that do not need to be crossed; a stoplight, in spite of having up to 2x the traffic of either of it's supplying streets, can handle only about 1/5 of the traffic of EITHER. Because cars must slow to a stop, the cars per minute throughput of an intersection is decreased. Since it must stop between cycles (so the intersection is utilized 0% for a few seconds) the throughput is further decreased. Since the other direction of traffic must be let through, the traffic throughput is cut in half and then some. Oh, and there's another one 4 blocks up.

It offers a longer route than just about any alternative. One is hard pressed to find a greater distance between two points (in a planned system) than the two short sides of a right triangle.

And frankly, it lacks imagination. The only reason to "design" (adopt is a more proper term) a grid is because you have no inclination towards city design in spite of the fact its your (rather important) job.

[jjune4991 1]

i like the left diagram, but since i live on a dead end street, i like the sort of security i have. it seems like there is no one going down that road except for the people who live in the 13 or so houses (or the idiots who dont know where they are going). my street is nice since it is accessable from a major road. but in my neighborhood, there are many streets that connect with each other and the 5 other major roads. my neighborhood is surrounded by 4 "avenues" (in sc4 sense) and 2 roads (sc4 sense) go through them, north and south. then we have a nice network of interconnecting streets and some dead ends. and it works, since you are connected, but have those options of the security. wow. i never thought i would rant about this...ever. so i say left mostly, with a couple rights!

[krbe 193]

The city where I grew up has a grid system (so that you can fire a cannon across town); however, the invention of cars, modern utilities, etc. has brought some problems to the grid system, and some nice new ideas have been developed for a restructuring of the city. Nothing is likely to happen though; they quite like their Renaissance city, with all its faults.

[ixnayonthetimmay 16]

Both have their shortcomings. While it is 'easier' to navigate a grid layout (for example, the 1 mile grids in most Western US Cities), it makes for longer travel in terms of distance, because unless you're traveling in a cardinal direction, you can never get somewhere "as the crow flies." Most people seem perfectly fine with driving three miles north plus four miles west rather than being able to drive five miles northwest.

And then take the street system in Los Angeles, London or Boston, for example..the only way to know where you're going is to have a firm grasp of the streets in your head already or you're bound to take a wrong turn. Nothing quite like a couple five-way intersections and missing turns on some roundabouts to make one despair....

I think the whole discussion is kind of moot, since the only perfect solution would be to allow each place a direct line to each other place, and the only way to achieve that is to turn all non-building space into open paved lot and send the cars out on a chaotic free-for-all. Anything less than that would mean an extra turn and an inconvenience for someone..

[david1314 44]

Grids are not easier to navigate...For example, to get to Downtown Denver from my parents house, you have to turn on Colorado Blvd, take Dry Creek, Take University, Cut across to Broadway (any street will do) and take Broadway in. If you miss any turn, you can easily become lost.

On the other hand, using my grandmother's house or aunts house (they live either side of London), I just get on to London Road and it takes me right in to The City.

Or perhaps if we were to keep just to Denver as a case study, I can use parker road and turn up in Downtown Denver or in Parker.

There is no doubt the grid complicates navigation (the fact many people grew up in the system and are used to it does not mean that it make more sense).

I like the comparison that rigid grids are like the rigid metric system and other networks are the imperial system. While the metric system can be described very simply, the imperial system gives much more useful measurements in terms of any given context (i.e. 1 pint make more sense as a measurement for ONE serving of drink than 475ml...). So, if universal cities are what you want (everyone copy Phoenix!) than the grid is good, but, if we enjoy the variety that makes cities different (nearly precursory to every member of this site in particular) grids are not a good thing.

Edit: Also, I feel the need to point out again that a road that goes North is nowhere near as useful as a road that goes to where you're going.

[Duke87 1,070]

Originally posted by: ixnayonthetimmay Both have their shortcomings. While it is 'easier' to navigate a grid layout (for example, the 1 mile grids in most Western US Cities), it makes for longer travel in terms of distance, because unless you're traveling in a cardinal direction, you can never get somewhere "as the crow flies." Most people seem perfectly fine with driving three miles north plus four miles west rather than being able to drive five miles northwest.quote>

Yes, but how many people are actually looking to go five miles northwest? People are looking to go in all sorts of directions, so you can't generalize and lay our roads every which way. On the other hand, there is something to be said for direct paths between major points of interest, so long as it's not at the expense of the grid. Washington DC is a fair example of this idea, though considering that the grid is rather sloppy (the blocks don't alays line up nicely), it certainly could have been executed better.

And then take the street system in Los Angeles, London or Boston, for example..the only way to know where you're going is to have a firm grasp of the streets in your head already or you're bound to take a wrong turn. Nothing quite like a couple five-way intersections and missing turns on some roundabouts to make one despair.quote>

Excellent point.

Originally posted by: david1314 The grid is a failed system. It does not offer the shortest route, the least traffic, the most efficient speeds, the fewest stops, or any compromise thereof. It mindlessly crosses roads that do not need to be crossed; a stoplight, in spite of having up to 2x the traffic of either of it's supplying streets, can handle only about 1/5 of the traffic of EITHER. Because cars must slow to a stop, the cars per minute throughput of an intersection is decreased. Since it must stop between cycles (so the intersection is utilized 0% for a few seconds) the throughput is further decreased. Since the other direction of traffic must be let through, the traffic throughput is cut in half and then some. Oh, and there's another one 4 blocks up.

It offers a longer route than just about any alternative. One is hard pressed to find a greater distance between two points (in a planned system) than the two short sides of a right triangle.

And frankly, it lacks imagination. The only reason to "design" (adopt is a more proper term) a grid is because you have no inclination towards city design in spite of the fact its your (rather important) job.quote>

Well, as any traffic engineer will tell you, with lights, timing is everything. You want to time the lights in sequence so that a driver going along a street hits as few red lights as possible. And New York actually does an excellent job of this. Provided there's no congestion, you can easily go 30 blocks up or downtown without hitting a red light on one of Manhattan's avenues. Of course, lights have also been known to be timed so that a driver hits as many red ones as possible quite intentionally so as to discourage drivers from using that road. Such is the insanity that is known as "traffic calming"- which is basically just a euphemism for "piss the driver off so they leave and don't come back". Anyways, the higher capacity alternative to traffic lights is grade-seperated crossings. Trouble is, they're more expensive to build, do not allow turning movements unless ramps are added, and oftentimes in cities there isn't really space for such things.

Originally posted by: Namesys I weren't in USA to taste those endless grid systems, but i'm sure i'd 10 times easier get lost in those grids where "everything seems the same" and you are in a maze or something like that. The ones on the righ

[david1314 44]

The easiest solution to traffic lights is is not grade separation, it's to not have them. Duh.

The traffic light removes the human factor from deciding the best way to handle the situation. Stopping at a red light at 4am is usually unrewarded. We all know a stupid red turn arrow that could easily be turned through safely (if you live in the US...and not Indiana with their ridiculous no left turn orb). We've all watched a green light when no cars were at intersection go red as our pack of cars approaches...then turn green just in time to stop the pack of traffic in the other direction, screwing EVERYONE.

So, if you cut roads down to higher frequency single lane roads with 3-way intersections that do not need lights (only 1 stop sign typically), you can hugely cut down on traffic. and radial roads (as opposed to grid) cut down on the need from cross-radial traffic (the biggest reason for stoplights that hinder city inflow). Also, if most stoplights are 3-way rather than 4-way, you centralize the commercial district along the radial road, and block traffic from crossing (by not having the 4th way), giving both a pull factor and push factor (respectively) to cut down cross radial traffic.

You can see it work in real cities, and you can try that in simcity... it works.

Oh, yeah, and then there's the fact that radial roads tend to upgrade to grade-separated controlled access roads much more favorably than do grid roads. Seriously, think about grid roads that are highways vs. radial roads that are highways. This is because they are where the heavy flow of traffic tends to be. Also, there is no grid development to cut across to achieve the ideal radial path.

[screamingman12 30]

Originally posted by: david1314 The easiest solution to traffic lights is is not grade separation, it's to not have them. Duh.

The traffic light removes the human factor from deciding the best way to handle the situation. Stopping at a red light at 4am is usually unrewarded. We all know a stupid red turn arrow that could easily be turned through safely (if you live in the US...and not Indiana with their ridiculous no left turn orb). We've all watched a green light when no cars were at intersection go red as our pack of cars approaches...then turn green just in time to stop the pack of traffic in the other direction, screwing EVERYONE.

quote>

There's an awnser to this, it's called the open circut traffic light, it uses sensor strips embedded in the road to congtrol the lights, and maximizes efficency. Removing the human factor is not a good thing in this case, if you have an intersection controlled by stop signs and someone runs it or can't see around an obstacle. The potential for a wreck increases dramatically, as there is no set legnth of time that you are required to stop at a stop sign.

So, if you cut roads down to higher frequency single lane roads with 3-way intersections that do not need lights (only 1 stop sign typically), you can hugely cut down on traffic. and radial roads (as opposed to grid) cut down on the need from cross-radial traffic (the biggest reason for stoplights that hinder city inflow). Also, if most stoplights are 3-way rather than 4-way, you centralize the commercial district along the radial road, and block traffic from crossing (by not having the 4th way), giving both a pull factor and push factor (respectively) to cut down cross radial traffic.

You can see it work in real cities, and you can try that in simcity... it works.

quote>

Single lane roads? yeah, just what I would like to be on if some moron is trying to parallel park/gets in a wreck/gets his car towed, etc. you allways need multiple lanes to allow traffic to go around obstacles. Also, by blocking traffic from crossing, you restrict access to your CBD (not necessarily some place where someone would want to open a store). The only reason that this works in SC is because commercial lots can be grown without road access.

Oh, yeah, and then there's the fact that radial roads tend to upgrade to grade-separated controlled access roads much more favorably than do grid roads. Seriously, think about grid roads that are highways vs. radial roads that are highways. This is because they are where the heavy flow of traffic tends to be. Also, there is no grid development to cut across to achieve the ideal radial path.quote>

You wouldn't convert a grid road to a highway, as it wouldn't be necessary. The shortest distance between two points os a streight line, and in your situation (circuitous, winding roads), traffic would have to make a lot of unecessary turns and direction changes. You also fail to take into account that a mass transit system (or even a simple bus system) would be much easier to institute and be much more effective in a grid arrangement.

New Urbanism, when paired with a mass transit system is a lot more effective at quelling traffic then a road arrangement that restricts driving.

[Jasoncw 11,840]

David, I think that the directness factor makes sense if you're laying a grid over an existing city, but if the city is built with a grid in the first place, then the city will develop around the grid. 

Also, the example of your parent's house isn't a good one.  Yeah, there's a grid, but it's mostly spaghetti.  The reason the drive is so bad is because the grid is not implemented enough.

Denver as a whole is a bad example though.  It is mostly orthogonal, but it is not grided.  Every few blocks there's a park or an industrial area which disrupts the grid.  If Denver was a good example of a gridded city, then you would theoretically only have to make one turn, not including entering the parking lot.  You would leave your house, travel down the road, and then turn onto the road on which your destination is located, and you would drive until you get to it. 

I personally like Detroit's plan, which was never really implemented in the way that it was intended.  In this plan, you have one chunk of plan, which can be repeated indefinitely in any direction.  It is in the same spirit as the grid, except that you can travel more directly (you can travel the hypotenuse).  At the same time though, there is a larger traditional grid overlaying all other systems which you can always fall back on if all of the other systems are too confusing.

While the plan looks soulless at first, I actually think it would be good for the community aspect of a city, and I also think it is a good urban plan.  Each small pie slice has its own pie park.  Each hexagon area has its own larger central park.  I think this would be something valuable for the community and for a sense of community ownership.  With the parks essentially being traffic circles, you could make the entire hexagon a large traffic circle park (this is not in the original plan as far as I know), creating a park with a one mile diameter, but without disrupting the logic of the system.  The same could be done with other geometries in the plan.

I think the only problem with the plan is that there's a traffic circle every mile, lol, but other than that I like it a lot.

Here's the plan.

[ixnayonthetimmay 16]

Response to David1314

I feel you were responding to me in your post immediately after mine, so on that assumption, I would like to respond back.

"Grids are not easier to navigate..."quote>

I should have clarified. It depends on the circumstances. I put the quotes in there, because although it is believed by me and many people I know that grid systems are easier to navigate, I know not all people would agree.

There is no doubt the grid complicates navigationquote>

If there were no doubt, why is this discussion even taking place?

..the fact many people grew up in the system and are used to it does not mean that it make more sense...quote>

The exact opposite could also be said about the non-grid-based street system. But I am not trying to champion the grid system over the non-grid system, but was rather trying to point out that neither are perfect. The main issue is that no system we have now fully addresses the problem of getting people from Point A to Point B in the fastest amount of time, and that's the main point I was trying to raise.

if we enjoy the variety that makes cities different (nearly precursory to every member of this site in particular) grids are not a good thing.quote>

The rigid, unyielding no-room-for-variations grid is not a good thing, I will be the first to admit. But does this mean that any grid setup must be thrown out for lack of originality? Variety is essential to prevent McSuburbs from spreading everywhere, and the grid layout is very conductive to bland repetitiveness. But still, if the New World consisted of cities built entirely on the same basis of European organic street layouts, wouldn't the same boring old grid layout be considered to include some much needed variety to the norm?

Edit: Also, I feel the need to point out again that a road that goes North is nowhere near as useful as a road that goes to where you're going.quote>

And I'd like to point out again that to always have a path going from where we are directly to where we want to be, we would need to pave over all non-built-up land and allow cars to have at it, like a bumper-car rally on a large scale. Plus, what if the street going due north goes just the way I needed to go?

[ixnayonthetimmay 16]

To Duke87...

I didn't clarify what I meant by "'easier' to navigate". By that, I meant that it has been my personal experience that finding my way around an unknown city laid out in a grid pattern is much easier than find my way around an unknown city that has streets going any which way and in any direction, turning and twisting and changing orientations so much that you can be driving slightly southeast one moment and heading north by northwest the next and still be on the same named road. That being said, ease of navigation to out-of-towners is not that strong an argument to use grids exclusively. You make a very good point about Washington D.C. and the fact that there are roads running straight through to major attractions, which was Pierre L'Enfant's original intent, I'm sure. But just ask those folks in Brasilia how effective the planned city plan is after the original architects have moved on. and the city keeps growing without the plan

[Duke87 1,070]

Originally posted by: david1314 The easiest solution to traffic lights is is not grade separation, it's to not have them. Duh.

The traffic light removes the human factor from deciding the best way to handle the situation. Stopping at a red light at 4am is usually unrewarded. We all know a stupid red turn arrow that could easily be turned through safely (if you live in the US...and not Indiana with their ridiculous no left turn orb). We've all watched a green light when no cars were at intersection go red as our pack of cars approaches...then turn green just in time to stop the pack of traffic in the other direction, screwing EVERYONE.quote>

Heh. Okay, now we're seeing how being from Denver versus being from New York makes a big difference. Namely, you frown upon "removing the human factor from deciding the best way to handle the situation". I'm trying to picture what driving in New York (Manhattan or otherwise) would be like with the human factor reintroduced.... and I'm coming up with little other than fenderbenders and arguments. People here don't get along well enough to handle traffic themselves. To put it in simple terms-

Western US:

"After you"

"Okay, thanks"

New York:

*both cars try and rush through first and crash into each other*

"Hey, {expletive}! What the {expletive} do you think you're doing?"

"What do you think I was doing, you {expletive}!? I was going through the {expletive}ing intersection! It was clearly my turn!"

"No it wasn't, you {expletive}ing {expletive}! Where the {expletive} did you learn how to drive!?"

etc, etc.

So, reintroducing the human factor... very bad idea around here.

...although, in Boston, it would make no difference. People from Massachusetts never pay attention to things like signs and traffic lights, anyway.

So, if you cut roads down to higher frequency single lane roads with 3-way intersections that do not need lights (only 1 stop sign typically), you can hugely cut down on traffic. and radial roads (as opposed to grid) cut down on the need from cross-radial traffic (the biggest reason for stoplights that hinder city inflow). Also, if most stoplights are 3-way rather than 4-way, you centralize the commercial district along the radial road, and block traffic from crossing (by not having the 4th way), giving both a pull factor and push factor (respectively) to cut down cross radial traffic.quote>

A radial system is an interesting idea. One which works well if done right, but it's a fragile balance- if you don't give it enough "spokes" with enough capacity it all of a sudden works against you. Just look at Moscow. The trouble with favoring 3 way intersections over 4 way ones is that it would be false to think that they "block traffic from crossing". Nay, what they do is force drivers to make a right turn onto and then a left turn off of the main road (or vice versa)- which puts additional strain on the main road and doubles the number of intersections necessary. Another image (MS Paint is getting a workout due to this thread!):

Notice what happens here. With two 3 way intersections, that center stretch of road carries four of the six possible movement pairs through this "node", while each intersection is used in five of them. With one 4 way intersection, no stretch of road carries more than two, although all six must pass through the same intersection. Still, there is only one intersection and only one traffic light as opposed to two. Nobody potentially needs to wait at a red light twice. Also, of the twelve total movements, six involve making a left turn in the top<

[david1314 44]

There's a few brief (edit) things I'd like to comment on:

Duke: Drivers with right-of-ways are how to handle the situation. I would actualy point to driver 'politeness' (it's better described as rudeness when you consider the traffic behind you're holding up) as a serious cause of traffic problems.

The human factor is ripe in the UK, and despite all non-proximate indicators to the contrary, they have among the safest roads in the world (narrow, heavy traffic, poorly signed...etc. all working against safety).

Blocking cross traffic is not only a function of pulling people away by blocking their access to the tangential (cross-radial) street. Traffic must also be pushed along the radial street, so that even if access were possible across the radial, it wouldn't be useful. You can't just take NYC and say a radial system would be best applied to the distribution of population in the city. But we should also recognize that since 1632 (in my research) the city of New York was built around a rigid grid...changing that now is impossible.

And while your pictures are nice, it doesn't change the fact that the on the first pic, the north-south traffic, on properly timed lights, does not affect the east-west traffic. You haven't shown the usefulness of a traffic light, but rather displayed its futility. Alternatively, if the north-south traffic filters in to a continuous stream of east-west traffic, the n-s traffic is disrupted while the e-w is not. In the case of a stoplight, the e-w AND n-s traffic is disrupted.

If applied to a radial system, all radial roads take precedent for light timing...so, you don't run into the same problems as deciding weather the cross-radial or to-town traffic is more important (as is so often the case with a grid). Or for that matter, determining if a street is cross-radial or to-town.

Jasoncw: regarding my Denver example (from my parent's house), it is not because a simple 1-turn grid does not exist (Dry Creek to Broadway is possible), it's that this is not the fastest way. And it really is a good example. all the roads I listed fit into the greater grid of Denver. They are ALL north-south or east-west (and only Broadway goes somewhere that's not north or west...incidentally, it also goes north)

Your point on Denver's grid is well taken though... there's is no doubt we are both jaded and influenced by our home grids

Screamingman12: Traffic lights with sensors are the norm in Denver. They taunt me by making me stop, then immediately changing to green after I've destroyed my gas-mileage. They fail.

And single-lane does not mean single-lane with no passing. A dashed yellow (in US) is plenty effective at solving ALL problems you've noted with a single lane system.

And finally, you're arguing the non-grid city like roads are placed by a random number generator. But they're not, they head to urban centers which is incidentally where people head. Thus, you have a road to where you're going, not a road to the north.

Ixnay: There is discussion because people become jaded and assume their own city has done it right...and their wrong. But is is an imperative that a road to where you're going is easier to navigate than a road going to the north that intersects a road to where you're going. The fact that this is an imperative means there is no debate to be had.

And I forget who posted it, but someone stated that a road to where your going means paving over everything. This statement is true...if we totally ignore any concept of city planning. If a city is planned and centralized with commercial districts shooting down its radial (even gridded cities apply this model), then all traffic necessarily goes down the radial. It is not that paving over a city wouldn't be useful for traffic, just that it's unnec

[hamsterTK 93]

I guess I was mixed up by this discussion because it's rare entire cities are planned from scratch and when they are they almost never work exactly like they should which is why I don't see the point in debating some of these things. Honestly, in reality roads are built when the need is there and traffic patterns are somewhat established. Besides grid streets are probably around because they were easy to survey and build. Just go straight.

My thinking is on the very localized scale of things, as in what layout is best for a residential neighborhood being built.

One person here already said something about privacy while it's also been mentioned that being able to directly walk somewhere is also an issue. I guess it's a question is how you can balance this. I have seen griddy subdivisions with limited entrances to the main arterials and all the neighborhood amenities on the inside, which effectively makes it some "private", while at the same time I have seen loops and cul-de-sacs which have pedestrian cut-throughs in them to allow people to make their way more easily.

[mightygoose 92]

from a drivers perspective the non grid layout is far easier to navigate as there is clearer definition of discrete landmarks. IE it doesnt look the same at every junction, you can have a fair idea whether you have been here before, plus, there are little to no alternative routes meaning it is easier to map the layout out in ones head and requires far less spacial awareness.

[ixnayonthetimmay 16]

david1314

The notion that the road that goes 'where I am going' is all well and good, when I actually need to go the way the road is going. And, quite honestly, I think the radial design addresses it better overall than a grid - if I needed to travel downtown in the morning and uptown in the evening. However, it isn't always the case. It would be ideal if people chose to live and work in the patterns city planners wanted them to, because a lot of the traffic problems shown wouldn't even be problems.

When I was a cable contractor, I was sent to job sites located in completely different parts of town. Sometimes, the best route to take would send me through downtown traffic, sometimes it was just up the street. Other times, it was miles out in newly-built areas, so I could smile as I drove hastily by the cars all lined up in the opposing lanes. And with my current job, my commute is about 14 degrees away from perpendicular to the ideal radial flow of traffic into town.

Basically what I'm trying to say is that while a lot of people are going to the same place, not everyone is. This is the case in smaller towns, I'm sure, but not large metropolitan areas with populations in the millions. Furthermore, having lived in Dallas, what I would consider a moderately decent example of a radial layout, I can attest to the logistical problems of trying to funnel people together in one small central area. And lastly, if such a radial system could be designed to move people the most efficiently from the fringes to the center, are you suggesting that the rest of us poor souls who aren't fortunate enough to have an office job downtown get the short end of the stick for commuting?

Would a perfect wheel-like layout work for a large city? Possibly it might. It might not even be feasible to ask such a question, at least for the case of any land that has already been remotely developed. After all, the only reason the grid design is so prevalent in the United States is because farms were laid out that way (thank you very much, Northwest Ordinance). Political and financial considerations included, I don't think people would very much like the heavy-handedness of a government claiming eminent domain and plowing up whatever the heck it needed to so that the city planners could ensure their design become a reality at all costs. But I suppose testing that hypothesis out is why we all have SimCity to begin with...

[david1314 44]

^ You have a point. But marginal numbers of people affect traffic little. Contractors do not factor in to traffic the same way commuters do. For the most part, their commute can be discounted in city planning (as none will be a regular commute and there will be many one-off commutes). It's really not a question of what SOME people need, but rather what most people need. You do not need to consider the ad hoc commutes of a contractor because by the time you've implemented that into the city planning, it's no longer a valid route still in use. And, the commute in question comes into play when bidding on jobs. So rather than having the relatively circular range that exists in a grid system, the range tends to be elongated by the highly trafficked radials. That is, you don't bid on jobs you can't drive to. This consideration applies within and without the grid. The point is moot.

The biggest problem with a grid is that it does not seek to solve any problems of commute. Rather, the only problem addressed by a grid system is minimizing human input during design phase (and maximizing it during the utilization [driving] phase).

City planning, on a macro level, deals with the aggregation of commutes. Only commuter poles (downtowns, biz districts, recreation districts, and shopping centers) draw large enough numbers of people that they become significant in planning. Because there is no statistical commonality between the non-mainstream commutes, you can't say that a road is useful or not useful for them. And as pointed out earlier, most of these commutes are a function of city layout and not of as-the-crow-flies proximity.

And remember, ring roads tend to be utilized in radial styled street layouts. Many cross radial commutes are not only addressed, but are actually shortened. If points are randomly selected around the city and joined, more often then not, a ring road with radial is a shorter distance (because it's got the circular path) while the grid must always be the sides of a rectangle. As you approach the Grid's cardinals (the road alignments), you may have a few commutes that are shorter with the rectangle, but the circle and radial method is shorter for any but this narrow swath of population. For example, if you're driving in Houston, from one decentralized point to another, chances are one of it's ring roads is your choice route...in spite of the grid.

I don't disagree with you that it would be difficult, nay impossible, to implement a radial system rigidly in a city that's been built with a grid...I know I wouldn't want one going through the grid that my house sits on (granted I-25 nearly does as it stands). But as far as future planning of cities, the masochism of the grid needs to stop.

[Shingure 56]

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Living in Philadelphia. Being one of the First US cities and the largest for a short time Grids are actually problematic. Here is my theory. If there are 200 small residential streets many of those residents will use a main road that 2000 people commute on. Almost all of those 2000 people and cars will then go onto a major atery of some sort and join thousands of passengers. This is the same in grids and with non grid organic street placements. In Philadelphia the traffic on the street that you live on may not be that bad. But when you drive to a semi-main thoroughfare then it gets alittle crowded but it's still moving. Turn onto a main thoroughfare and the traffic slows things down and ontop of that more commuters use the main roads like blood cells in the circulatory system. Highways are ultimately the thing used by passengers no matter what place you go to. Even though I tend to see non grided systems more in Europe there arent many here where Iam at. Even the suburbs here follow a grid pattern to a certain extent.

Also to add what david1314 about the grid being a failed system. It is only a failed system because America has millions and millions of cars. More than any other country. That's why it fails. The conseption of these road systems in the Northeast and Eastern part s of the US were in the Colonial era. Philly has made an effort to try to keep their roads up to speed with advances in technology. Also what makes the non grid system a failure. Non grids are actually harder to deal with. In terms of subway construction non grided streets above makes it hard to actually plan routes. Some routes over here in America can follow these streets because they are grided a certain way. Because when building subways there arent alot of curves involved with building subway routes. Sure they will leave the trail of the road once in a while in the grid system. But they usually end up under or in some circumstances over another road.

To add again. In Philadelphia we have thing called One Way Streets. These streets allow traffic to move more smoothly in medium density areas. Hence the Philadelphian grid system is one of the better ones. Even though it needs some updating and improving. Some streets are too narrow and some space is used incorrectly. But all in all Philadelphia was finely planned in the first place. Which means that the rest of the city was to also follow suit. Until areas like Northeast , Mount Airy and Germantown , and Other outer lying areas within the county had a grid that was fluid. The grid was modified also for geological reasons. Because in Philly We have sharp drops into small bodies of water. Meaning in some places you will be looking down on streets winding though the park and be looking up looking at houses 100ft or so higher than you are. Each city has a reason in their madness.

Ugh again, To add onto what Duke was saying about those intersections he is right. Also cities are cheap like that. They dont want to pay for 3 way intersections. They want one 4 way intersection. Ive seen cases where there are 5 way or 6 way intersections.

[confused04 14]

I've never found navigating grids very difficult at all. In fact, I live in a heavily gridded neighborhood in a gridded city (MSP, MN). I think many people are assuming that all streets in a grid carry equal weight and diffuse the traffic to keep it "even" which is definitely not the case. Most grids have primary grid lines (much like a graph where every tenth line is bold) which carries most of the traffic to an even greater road (much like the X and Y axis). I never find one square to look much like the previous at all. I had a friend from England come over here and he learned to navigate it very quickly. What makes it particularly easy is describing a destination as an intersection, such as "Randolph and Victoria". Which makes carrying directions typically unnecessary if you're even remotely familiar with the area. Gridded roads are littered with landmarks as well to aid in navigation. If a grid is disrupted, you know how to get back on to the road you're on. If the grid is still intact over all, then you can just take the border roads that outline the "disruption" and get back on course. If you are unfamiliar with the area that doesn't have grids and you get lost and might not be able to find your way back onto the right path. Human brains are programmed to follow and recognize patterns (the mind will even find patterns if you hit random notes on a piano). By definition, irregular roads lack such a pattern and could lead people astray.

Grids are also quite efficient. Just because roads intersect, it doesn't mean they have traffic lights and traffic patterns will be easily predictable. Earlier it was state that grids are failures and I don't think there's anyway to call it a "failure".