Eternal commute .

[Richie99 159]

Hello I would like to know whether the phenomenon of eternal commute can be deduced from transportation queries and also what type of region layout is prone to this bug?

I hav four cities in my region.A,B and C are in a line with a highway running through them.They are adequate ramps goin into job areas with lots of bus stops.

City D is adjacent to A with the only connection been a ferry terminal since there is no land between A and D.

Am I likely to experience eternal commute?

[JJogurt 18]

Your cities are in a line, so no, you can't get the commuter loop bug.

 

Here's my illustration of the bug. The residentials (green) always take what they think is the shortest route to their workplace (yellow). They think the shortest route is to go to the neighboring city, but they don't really know anything about that city's layout, so they end up spinning in an endless loop .

 

You can identify the bug by getting enormous traffic on your neighbor connections. To avoid it, you should should branch out your regional transportation network like a tree.

 

I hope the image makes any sense to you.

 

[Kuewr665 40]

Would placing employing buildings on the corners of a city work at all?

[dlsni 156]

To avoid it, you should should branch out your regional transportation network like a tree.

I've never understood what this means

[Prophet42 1,503]

dlsni -    Like a tree, your transportation network would have a trunk (like a highway) that runs through several cities.  From this trunk you would attach you 'branches' (avenues and roads). The only way for a Sim to get from town A to town B or C would be to travel on the 'trunk'.  In JJogurt's example, you would have a highway run from A to B to C.  Roads would attach to the highway in each individual city but would not cross the city border.  This way for a Sim to travel from A to C he/she would have to enter the highway in A and exit the highway in C.  With this scenario, there would be no way for the pathfinder to find a loop back to A (other than going back the way it came, which it will not do) thereby eliminating the possibility of the eternal commuter bug.

[SimRico 968]

Your cities are in a line, so no, you can't get the commuter loop bug.

 

Here's my illustration of the bug. The residentials (green) always take what they think is the shortest route to their workplace (yellow). They think the shortest route is to go to the neighboring city, but they don't really know anything about that city's layout, so they end up spinning in an endless loop .

 

You can identify the bug by getting enormous traffic on your neighbor connections. To avoid it, you should should branch out your regional transportation network like a tree.

 

I hope the image makes any sense to you.

 

Does the eternal commute-commute loop bug refer to say, when i click the Route Query and click a resident to check the commute that theres no destination b"t instead the green commute arrows goes into a repeated-'circular' route-never returning home and never reaching a work destination?. How can i replicate this?

[APSMS 1,893]

Eternal commuters only exist across city borders. I have had this bug before. it was identified by noticing that travelers went from a neighbor connection on one edge straight through to the adjacent edge city connection. A very thick green line of commuters from one edge to the other, and very obvious. Found via heavy traffic, and querying the neighbor connection.

[Richie99 159]

Thanks everyone esp Jogurt for that wonderful suggestion.Could not see the image though due to my browser but I quite understand what you mean.

[Richie99 159]

So does it occur only on roads?

[SimRico 968]

I think @jjogurt's excellent illustrated graph and description deserve a one-up in his post #2.  I would not have known how to research this bug.  

[adam forrest 51]

Very interesting. I did not know about this because i generally have enough jobs in ea tile in my new region so far. Although that does not mean I may never come across it. Now I can plan ahead a little more and have measures in place to avoid this. Thanks for your question richie otherwise I would not have known. Thanks jjogurt for that great description of the tree network and the pic.

[A Nonny Moose 8,262]

One of the main offenders in this loop is the ferry.  Ferries are almost like Star Trek transporters, especially between cities.  You can detect a loop if there are more commuters on a route than you have in your city population.  Usually loops involve several different modes of transportation.

 

You can either break the loop or take advantage of it by putting toll stations on it at each border.  You can enrich your cities this way.

[z1 566]

So does it occur only on roads?

 

Oh, no.  The Sims will take any form of transportation they can to get out of going to work.  Roads, subways, highways, el rail, monorail - you name it, they'll take it.  And they'll switch back and forth as many times as they have to.

 

Anything to get out of working.

[CGMozart118 14]

Any type of transportation is vulnerable - in my new region (already! ugh) of just about all large tiles I have sims take the bus from city A to city B, pick up the train (heavy rail) in city B, and take the train into city C, where they...disappear? Ugh - city C was supposed to be the industrial city, direct access to both cities A and B - I was trying to get them to just go directly to it, e.g. train from A to C, train from B to C (the city tiles are offset), no multi-city crossing, no bug, right? Nope.

In this region I have almost a 1:1 job/sim ratio (not good, I know, I know, I messed up early trying to get a jump on the eternal commuters by having too many jobs) and folks will still drive past commercial and industrial areas to avoid work, like Z said...

...was Maxis trying to make a statement on that one? I've had sims walk from A to B, grab a bus in B, and go on to C, even when it meant crossing half a large city tile to get to the stop. *facepalm*

[timmie 988]

Any type of transportation is vulnerable - in my new region (already! ugh) of just about all large tiles I have sims take the bus from city A to city B, pick up the train (heavy rail) in city B, and take the train into city C, where they...disappear? Ugh - city C was supposed to be the industrial city, direct access to both cities A and B - I was trying to get them to just go directly to it, e.g. train from A to C, train from B to C (the city tiles are offset), no multi-city crossing, no bug, right? Nope.

In this region I have almost a 1:1 job/sim ratio (not good, I know, I know, I messed up early trying to get a jump on the eternal commuters by having too many jobs) and folks will still drive past commercial and industrial areas to avoid work, like Z said...

...was Maxis trying to make a statement on that one? I've had sims walk from A to B, grab a bus in B, and go on to C, even when it meant crossing half a large city tile to get to the stop. *facepalm*

 

Your problem is not an eternal commuter bug, it's just that you don't have the jobs your sims are looking for. A sim from R$$ will not do just any job. The same for the other wealth levels!

[CGMozart118 14]

 

Your problem is not an eternal commuter bug, it's just that you don't have the jobs your sims are looking for. A sim from R$$ will not do just any job. The same for the other wealth levels!

 

Yet I have many many jobs - is it solely that they aren't the right jobs? I've got low to no demand (negative for some) in any of the commercials or industrials, except agriculture (yep, I have SPAM), but at the same time high demand for R$/R$$ and medium demand for R$$$. I'm going on the high number of "abandoned due to commute time" messages, and sims that seem to travel into an adjacent city, just to hitch a ride into yet a third city. Or am I missing something? Will it still show that when the wrong jobs are present?

[Richie99 159]

I have ferries all over the place but I don't think I should be bothered cos there are monorails to take the sims right from the ferry stations.Whether eternal commute or not,I enjoy watching the long chain of train moving on my monorails:)

[WeBuiltThisCityOnSimCity 40]

It plagued my big megacity and now the downtown core of the central city is a ghost town.

[A Nonny Moose 8,262]

That shouldn't happen.  It is not a symptom of the ECB, but some failure to move traffic through the area.  Check your network paths.

[longhorn 25]

My older cities in my region still have this problem, but in my newer cities I minimize neighbor connections and have last ditch employment available at the edge of the tile.  If you have a "downtown" city, it helps to eliminate rail stations in all areas of the tile except the center, so that way you trap rail commuters from other cities in your city center.  I'll still get the occasional few who will still try to get out of town rather than work, and I'll get the rare few who will walk across an entire city tile as well, but for the most part, it works.

[A Nonny Moose 8,262]

Try slamming toll gates on all the routes out of town.

[z1 566]

If you have a "downtown" city, it helps to eliminate rail stations in all areas of the tile except the center, so that way you trap rail commuters from other cities in your city center.

 

This usually doesn't work.  I've done this, forcing my Sims to take the subway to the center of town and then dumping them there, right in the middle of vacant office buildings.  They then happily get on a bus, train, or whatever, and head straight for the border.

 

The reason this happens is that the traffic simulator's destination finder first looks around for the closest jobs, where a border is considered a job location if there's sufficient demand on the other side.  The destination finder doesn't take paths into account (that's not its job); it just looks at straight-line distances.  Once it finds the job with the shortest distance "as the crow flies", it hands the destination off to the pathfinder, which then has to get the Sims to that destination.  If the only way to do that is to take them all over town and past Robin Hood's barn on the way, passing many suitable open jobs, it will do so.

 

To sum up, the Sims decide their destination before they begin their trip, with no concern for how they're going to get there.  That decision is irreversible, as long as the destination can be reached.

[A Nonny Moose 8,262]

That's an interesting fly in the ointment, and I've never realized that.  Perhaps the destination finder should be biased to the local tile, but I suppose that'd mean a fix to the exe.

[spa 970]

That's an interesting fly in the ointment, and I've never realized that.  Perhaps the destination finder should be biased to the local tile, but I suppose that'd mean a fix to the exe.

 

If a preference for in tile could be setup, that would solve a lot of problems!

[z1 566]

Perhaps the destination finder should be biased to the local tile, but I suppose that'd mean a fix to the exe.

 

It would.  And even that by itself wouldn't be sufficient.  If the border that has jobs beyond it is ten tiles away, and the jobs in the local tile are thirty tiles away, where do you go?  If the adjoining tile is a large tile, the jobs could be anywhere.  And if you make the local tile preference too strong, you break the whole demand dependence between tiles.

 

If you had access to the source, the easiest solution would be to tag each Sim with its originating tile, and then you never let that Sim re-enter that tile.  End of eternal commuter bug.

[A Nonny Moose 8,262]

Unfortunately it just shoves the problem out one level.  What if such a tagged Sim went to the next but one tile then came back, and bounced back and forth with no job.  I think you'd have to tag the object with a list of tiles entered as well which would no doubt raise absolute hell with the speed of the simulation even if you used hashed lists.  However, I do like the idea of forbidding back-tracking looking for a job.

[z1 566]

What if such a tagged Sim went to the next but one tile then came back, and bounced back and forth with no job.

 

Can't happen, for the same reason that you can't get an Eternal Commuter Loop with just two tiles.  When a Sim has entered a tile, the game is smart enough not to let him go back to the tile from which he just came.

 

One might also think that a Sim could enter a three-tile Eternal Commuter Loop from a fourth tile, but when you consider the geometry involved, that's extremely hard to construct.  It's not the type of thing that is likely to happen by accident.

[Linoa06 1,374]

Lol, there's a Doctor Who episode about eternal commuting.

[CGMozart118 14]

 

If you had access to the source, the easiest solution would be to tag each Sim with its originating tile, and then you never let that Sim re-enter that tile.  End of eternal commuter bug.

This is a dumb question that reveals why I mostly tend to break computers, rather than program them, but would it be possible to make some kind of mod that does that tagging WITHOUT going into the source? A mod that works like a tripwire or something that runs "after" and tags commuters?

[Ro-Bo 183]

Seeing that even NAM, the ultimate transportation mod, doesn't solve the problem, probably no way to solve it without messing with the source.