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Hi, Sha from Trulia here. I worked on some of the frontend aspects of this visualization and would be happy to answer any questions. We're pulling in OSM road d

Hi, Sha from Trulia here. I worked on some of the frontend aspects of this visualization and would be happy to answer any questions. We're pulling in OSM road data and published GTFS files for public transit routing. I just linked to SF but you can also search for other cities: http://www.trulia.com/local#commute/new-york-ny http://www.trulia.com/local#commute/new-york-ny http://www.trulia.com/local#commute/miami-fl http://www.trulia.com/local#commute/miami-fl http://www.trulia.com/local#commute/austin-tx http://www.trulia.com/local#commute/austin-tx

erode 14y ago
Not really applicable to me it seems. I commute across the Twin Cities in Minnesota in about 50 minutes but it wouldn't even calculate my times due to it being "well over 60 minutes" which is the max the filter will apply. How useful can you expect this to be, since commuting times can vary wildly even if you begin your commute 10 minutes earlier?
- nostromo 14y ago
  You're being too critical. This isn't a website to tell you your exact commute time. If you want that, try Google Maps. This is to show you roughly estimated travel times in all directions when you're looking at purchasing real-estate. And I think it works very well for that.
- benajnim 14y ago
  Seems inaccurate for my commuting times to various points in the metro as well. Looking at Broadway running east-west to the north of downtown, its a major thoroughfare that can take you to several major highways but its not being reflected.
pacaro 14y ago
This is cool, however I notice that your transit commute times are more optimistic that drive times in some places. For example, from downtown Kirkland, WA. You have the bus being faster than driving, there is no HOV lane that would explain this, my real commute choice is driving (10-15 minutes) or bus (35-40 minutes) but your heat map pretty much inverts those numbers.
peterwwillis 14y ago
Is this the absolute worst-case commute times? It never takes me that long to commute into/out of miami, or baltimore, or fort lauderdale. More like half the time. DC actually seemed like it went the opposite way as it usually takes an hour and a half to get from VA through the beltway into DC while the map showed only an hour for as far out as Dale City. A half hour (or more) from Petworth into Downtown during rush hour is fair, since DC has probably the slowest crappiest drivers in the nation. Updated theory: these commute times might not be based on actual driver data, it's probably a very rough estimation based on distance, travel time, speed limit, and population. It needs to be weighted based on the curve of traffic based on time and the way locals drive. Boca commuting will probably be slower than Miami commuting on average, unless you're on the highway in which case you're totally screwed in Miami. Not to mention anywhere there's an on-ramp with lots of flow you're going to make a choke point, so times would increase a lot, unless you started after that exit. tl;dr Traffic is hard.
- imcqueen 14y ago
  I'm seeing the same thing. It says Bedford to Stamford is 45 minutes, it's actually about 25 minutes.
  - martincmartin 14y ago
    When do you commute? It says Cambridge to Bedford is about an hour, which is true at the start/end of rush hour. It's usually more than that if I get in my car after 3:30pm or before 6pm. P.S. Hi from Bedford, MA. :)
- jarrettcoggin 14y ago
  As far as I can tell, this must be the case. I'm just north of Boca Raton, FL and from where I live to work is about 8-10 minutes, not the 25-30 this is saying. EDIT: The only time it has taken 30 minutes was when I had to wait on two trains.
- ap22213 14y ago
  Agreed on DC - the places that I plugged in from northern va. (22102, 22213, 22046, etc.) all seemed to be showing the best-case times. Some places that it says are a 5-10 commute are more like 30-45 minutes at rush hour. Also, not related to the commute times, but the crime rates look strange. At least, it's showing Arlington, VA as almost completely red (very high crime). Maybe the data is right, but that would be surprising for one of the richer, more yuppified areas of the US.
nostromo 14y ago
This is super cool! It's more of a backend question, but what algorithm are you guys using to traverse the maps? Also, why did you decide to use Google for the display maps, when you used OSM for the backend calculations?
- Yen 14y ago
  Hi, Talin from Trulia. The times are calculated with a simple Djikstra's traversal, implemented in the open-source pgRouting (pgrouting.org) Our existing local information pages were already using google maps, so we didn't go out of our way to create new base maps just for this visualization.
- deleted 14y ago
  [deleted]
elliottcarlson 14y ago
Thanks - it actually seems close to accurate for me - though I have an approximate 2 hour commute door to door so it's purely guessing on the remainder of the trip. Will the outer boroughs of NYC receive transportation options as well?
- pavel_lishin 14y ago
  Where do you live and work? 4 hours of commute a day seems ... excessive. (I'm guessing, based on your question, that you work in NYC but live in another state, and probably spend most of those two hours sitting on a train, which would make it less, uh, awful-seeming.)
  - elliottcarlson 14y ago
    Sadly, I live in Staten Island, still one of the boroughs. I live on the southern end of the island, and work near the Empire State Building. While it is indeed excessive, it's on a nice comfortable tour style bus so I get an extra 2 hour nap time in the morning and can get work done on my way home - and I save more money due to far lower rent.
MetalMASK 14y ago
Hi Sha, Great work. I checked commuting time for Seattle, WA using public transit and most of your visualization are spot on. Is the public GTFS files you are referring to come from here: http://code.google.com/p/googletransitdatafeed/wiki/PublicFeeds http://code.google.com/p/googletransitdatafeed/wiki/PublicFe...? With regard to some of the earlier replies saying that the map is inaccurate, it might be worthwhile to use Amazon Turk to run some evaluation on how reliable the spatial data (or your algorithm for calculating travel time, rural vs local, .etc) is. -Sen
- Yen 14y ago
  We retrieved a list of U.S. agencies with GTFS feeds from gtfs-data-exchange.com, which is a very excellent resource :)
- shashashasha 14y ago
  Sen, that is a great idea. We're definitely trying to get this as accurate as possible (not having a public traffic data source makes this hard), and Turk would go a long way towards answering questions about places we don't have a good sense for (even all these comments are great for us to fine tune our calculations).
deleted 14y ago
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dkarl 14y ago
Times seem inflated in Austin, too. The smaller the time, the greater the error. The ten-minute area should be two or three times larger, but the 45-minute area bears some resemblance to rush-hour reality. Also, every route seems to be treated the same. In the morning, the road I live on is always empty in one direction and congested in the other. I used to commute against traffic and now go the same way as everybody else, and I could go twice as far in ten minutes as I can now. The numbers will never be accurate until you ground them in real traffic data.
- Zimahl 14y ago
  It appears that non-freeway streets seem way off, with freeway travel closer to being accurate. For example, Beaverton, OR, into Portland. Where I live it's at most, even at rush hour, 15 minutes to one of the two freeways near my house and this is estimating 30-35 minutes. The entire (house -> downtown) calculation is close (about 45 minutes downtown) but only for rush hour. Other than if there was an accident on I-5, there isn't a possibility of taking 50-55 minutes to get from my house to Tigard or Tualatin without spending 30 minutes lounging at Starbucks along the way. Looking at the data a little more, surface streets seem to simply be an estimate outward radially, with what appears to be very little taken into account otherwise. The freeways seem to be good, educated guess estimates.
- lallysingh 14y ago
  Funny, commute times for both me and my wife in the NJ/NY area are longer than those listed here. That said, it's not too far off, and useful for when we buy a home.
illumin8 14y ago
Great project. Would you please allow the slider to increase to values greater than 60 minutes? Unfortunately some of us poor souls in the Northeast regularly have 2 hour commutes into NYC.
swalsh 14y ago
Hi, as a person looking for a home in Boston I've used every tool out there. Amongst your competitors I find myself gravitating back to you and Zillow for the superior user interface. I love you for being able to click "search entire map". However the main problem I have during my real estate search has nothing to do with UI. It seems like for every home I find through the site that I contact a realitor about the home is already "under agreement". If your site could find a way to be more up to date about those things, it would really stand apart.
- SFPierre 14y ago
  We take this very seriously and work on improving data quality constantly. Thank you for the feedback! We definitely care about this.
ashr 14y ago
I agree with the other observations here that the timings aren't even in the ballpark. For North Denver Metro area, it is displaying 50-60mins for places that are 25 mins away in rush hour.
trhtrsh 14y ago
Can you fix this: http://www.trulia.com/local#crimes/san-francisco-ca http://www.trulia.com/local#crimes/san-francisco-ca so that it is normalized by population density? Otherwise it's completely misleading and uninformative.
aw3c2 14y ago
Do you take speed limits of the streets in consideration?
cbr 14y ago
Have you considered making a map where the color at each point is the average commuting time from there to all points within a radius? For example: http://www.jefftk.com/news/2010-11-17.html http://www.jefftk.com/news/2010-11-17.html The maps you've added are awesome when you know where you're looking at, but if you don't yet have a place picked out then knowing where to look is good too. A naive way to compute the kind of summary map I'm interested in is to just make the color at each point on your summary map be the average color on your map for a specific place. Something smarter could weight points by their desirability (I care more about how fast it is to downtown than to an arbitrary point in a suburb) but the naive version is pretty useful on it's own.
bapbap 14y ago
For the non-technical, what are you using to create/draw the overlay heat maps? I thought it might be some sort of tile server but it seems to be drawn using JS?
- Yen 14y ago
  Hi, Talin from Trulia here. For commute, our heatmaps are rendered in canvas, based on JSON data from our servers. This allows for the efficient slider. We also have static image tiles, for certain (ahem) browsers that don't support canvas. The downside is that they can't use the slider.

erode 14y ago

Not really applicable to me it seems. I commute across the Twin Cities in Minnesota in about 50 minutes but it wouldn't even calculate my times due to it being "well over 60 minutes" which is the max the filter will apply. How useful can you expect this to be, since commuting times can vary wildly even if you begin your commute 10 minutes earlier?

nostromo 14y ago
You're being too critical. This isn't a website to tell you your exact commute time. If you want that, try Google Maps. This is to show you roughly estimated travel times in all directions when you're looking at purchasing real-estate. And I think it works very well for that.
benajnim 14y ago
Seems inaccurate for my commuting times to various points in the metro as well. Looking at Broadway running east-west to the north of downtown, its a major thoroughfare that can take you to several major highways but its not being reflected.

pacaro 14y ago

This is cool, however I notice that your transit commute times are more optimistic that drive times in some places. For example, from downtown Kirkland, WA. You have the bus being faster than driving, there is no HOV lane that would explain this, my real commute choice is driving (10-15 minutes) or bus (35-40 minutes) but your heat map pretty much inverts those numbers.

peterwwillis 14y ago

Is this the absolute worst-case commute times? It never takes me that long to commute into/out of miami, or baltimore, or fort lauderdale. More like half the time. DC actually seemed like it went the opposite way as it usually takes an hour and a half to get from VA through the beltway into DC while the map showed only an hour for as far out as Dale City. A half hour (or more) from Petworth into Downtown during rush hour is fair, since DC has probably the slowest crappiest drivers in the nation. Updated theory: these commute times might not be based on actual driver data, it's probably a very rough estimation based on distance, travel time, speed limit, and population. It needs to be weighted based on the curve of traffic based on time and the way locals drive. Boca commuting will probably be slower than Miami commuting on average, unless you're on the highway in which case you're totally screwed in Miami. Not to mention anywhere there's an on-ramp with lots of flow you're going to make a choke point, so times would increase a lot, unless you started after that exit. tl;dr Traffic is hard.

imcqueen 14y ago
I'm seeing the same thing. It says Bedford to Stamford is 45 minutes, it's actually about 25 minutes.
- martincmartin 14y ago
  When do you commute? It says Cambridge to Bedford is about an hour, which is true at the start/end of rush hour. It's usually more than that if I get in my car after 3:30pm or before 6pm. P.S. Hi from Bedford, MA. :)
jarrettcoggin 14y ago
As far as I can tell, this must be the case. I'm just north of Boca Raton, FL and from where I live to work is about 8-10 minutes, not the 25-30 this is saying. EDIT: The only time it has taken 30 minutes was when I had to wait on two trains.
ap22213 14y ago
Agreed on DC - the places that I plugged in from northern va. (22102, 22213, 22046, etc.) all seemed to be showing the best-case times. Some places that it says are a 5-10 commute are more like 30-45 minutes at rush hour. Also, not related to the commute times, but the crime rates look strange. At least, it's showing Arlington, VA as almost completely red (very high crime). Maybe the data is right, but that would be surprising for one of the richer, more yuppified areas of the US.

nostromo 14y ago

This is super cool! It's more of a backend question, but what algorithm are you guys using to traverse the maps? Also, why did you decide to use Google for the display maps, when you used OSM for the backend calculations?

Yen 14y ago
Hi, Talin from Trulia. The times are calculated with a simple Djikstra's traversal, implemented in the open-source pgRouting (pgrouting.org) Our existing local information pages were already using google maps, so we didn't go out of our way to create new base maps just for this visualization.
deleted 14y ago
[deleted]

elliottcarlson 14y ago

Thanks - it actually seems close to accurate for me - though I have an approximate 2 hour commute door to door so it's purely guessing on the remainder of the trip. Will the outer boroughs of NYC receive transportation options as well?

pavel_lishin 14y ago
Where do you live and work? 4 hours of commute a day seems ... excessive. (I'm guessing, based on your question, that you work in NYC but live in another state, and probably spend most of those two hours sitting on a train, which would make it less, uh, awful-seeming.)
- elliottcarlson 14y ago
  Sadly, I live in Staten Island, still one of the boroughs. I live on the southern end of the island, and work near the Empire State Building. While it is indeed excessive, it's on a nice comfortable tour style bus so I get an extra 2 hour nap time in the morning and can get work done on my way home - and I save more money due to far lower rent.

MetalMASK 14y ago

Hi Sha, Great work. I checked commuting time for Seattle, WA using public transit and most of your visualization are spot on. Is the public GTFS files you are referring to come from here: http://code.google.com/p/googletransitdatafeed/wiki/PublicFeeds http://code.google.com/p/googletransitdatafeed/wiki/PublicFe...? With regard to some of the earlier replies saying that the map is inaccurate, it might be worthwhile to use Amazon Turk to run some evaluation on how reliable the spatial data (or your algorithm for calculating travel time, rural vs local, .etc) is. -Sen

Yen 14y ago
We retrieved a list of U.S. agencies with GTFS feeds from gtfs-data-exchange.com, which is a very excellent resource :)
shashashasha 14y ago
Sen, that is a great idea. We're definitely trying to get this as accurate as possible (not having a public traffic data source makes this hard), and Turk would go a long way towards answering questions about places we don't have a good sense for (even all these comments are great for us to fine tune our calculations).

deleted 14y ago

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deleted 14y ago
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dkarl 14y ago

Times seem inflated in Austin, too. The smaller the time, the greater the error. The ten-minute area should be two or three times larger, but the 45-minute area bears some resemblance to rush-hour reality. Also, every route seems to be treated the same. In the morning, the road I live on is always empty in one direction and congested in the other. I used to commute against traffic and now go the same way as everybody else, and I could go twice as far in ten minutes as I can now. The numbers will never be accurate until you ground them in real traffic data.

Zimahl 14y ago
It appears that non-freeway streets seem way off, with freeway travel closer to being accurate. For example, Beaverton, OR, into Portland. Where I live it's at most, even at rush hour, 15 minutes to one of the two freeways near my house and this is estimating 30-35 minutes. The entire (house -> downtown) calculation is close (about 45 minutes downtown) but only for rush hour. Other than if there was an accident on I-5, there isn't a possibility of taking 50-55 minutes to get from my house to Tigard or Tualatin without spending 30 minutes lounging at Starbucks along the way. Looking at the data a little more, surface streets seem to simply be an estimate outward radially, with what appears to be very little taken into account otherwise. The freeways seem to be good, educated guess estimates.
lallysingh 14y ago
Funny, commute times for both me and my wife in the NJ/NY area are longer than those listed here. That said, it's not too far off, and useful for when we buy a home.

illumin8 14y ago

Great project. Would you please allow the slider to increase to values greater than 60 minutes? Unfortunately some of us poor souls in the Northeast regularly have 2 hour commutes into NYC.

swalsh 14y ago

Hi, as a person looking for a home in Boston I've used every tool out there. Amongst your competitors I find myself gravitating back to you and Zillow for the superior user interface. I love you for being able to click "search entire map". However the main problem I have during my real estate search has nothing to do with UI. It seems like for every home I find through the site that I contact a realitor about the home is already "under agreement". If your site could find a way to be more up to date about those things, it would really stand apart.

SFPierre 14y ago
We take this very seriously and work on improving data quality constantly. Thank you for the feedback! We definitely care about this.

ashr 14y ago

I agree with the other observations here that the timings aren't even in the ballpark. For North Denver Metro area, it is displaying 50-60mins for places that are 25 mins away in rush hour.

trhtrsh 14y ago

Can you fix this: http://www.trulia.com/local#crimes/san-francisco-ca http://www.trulia.com/local#crimes/san-francisco-ca so that it is normalized by population density? Otherwise it's completely misleading and uninformative.

aw3c2 14y ago

Do you take speed limits of the streets in consideration?

cbr 14y ago

Have you considered making a map where the color at each point is the average commuting time from there to all points within a radius? For example: http://www.jefftk.com/news/2010-11-17.html http://www.jefftk.com/news/2010-11-17.html The maps you've added are awesome when you know where you're looking at, but if you don't yet have a place picked out then knowing where to look is good too. A naive way to compute the kind of summary map I'm interested in is to just make the color at each point on your summary map be the average color on your map for a specific place. Something smarter could weight points by their desirability (I care more about how fast it is to downtown than to an arbitrary point in a suburb) but the naive version is pretty useful on it's own.

bapbap 14y ago

For the non-technical, what are you using to create/draw the overlay heat maps? I thought it might be some sort of tile server but it seems to be drawn using JS?

Yen 14y ago
Hi, Talin from Trulia here. For commute, our heatmaps are rendered in canvas, based on JSON data from our servers. This allows for the efficient slider. We also have static image tiles, for certain (ahem) browsers that don't support canvas. The downside is that they can't use the slider.