Time Dependent data feeds Was: Re: [pgrouting-dev] Time dependent data and input format

[Stephen Woodbridge]

Jay,

There are three areas at the moment that use time dependent data in one 
way other the other:

1. Your work which is probably most accurately aligned with traffic 
feeds or other historical traffic speed information.
2. Kishore's work which is looking at statistical planning based on 
schedules
3. Multi-modal routing based on schedules and exact transfer times

When these get reduced to graph theory problems, the differences have 
more to do with how costs are assigned, ie how the shedule info is 
organized into the weights and how they are fetched based on time. The 
basic algorithms pretty much the same. Kishore's work may be somewhat if 
an exception, I have not followed that as well, but I think at one point 
I presented an argument that he could implement his work by remapping it 
into your time dependent work, so it might be valid also.

On 8/9/2011 11:16 AM, Jay Mahadeokar wrote:
> Hi,
>
> Sorry, I somehow missed this and did not reply earlier.
>
> On Fri, Jul 29, 2011 at 11:44 PM, Stephen Woodbridge
> <woodbri at swoodbridge.com <mailto:woodbri at swoodbridge.com>> wrote:
>
>     Jay,
>
>     Starting a new thread here!
>
>     This looks interesting.
>     http://www.511.org/developer- resources_traffic-data-feed. asp
>     <http://www.511.org/developer-resources_traffic-data-feed.asp>
>
>     Click on the TRANSIT menu item - this is the application we want to
>     build :)

Ok, there is a LOT of features and function on this page and it is hard 
to see all of them. But it does appear to do multi-modal (3) and support 
traffic time dependent routing, among other stuff.

At the time, you were looking for time dependent traffic data and this 
site did have some API's and I thought a traffic feed, but even it not a 
feed, it is representative of the features and functions that we would 
like in pgRouting if we were to build a site like this.

-Steve

> This looks more relevant to Kishore's algorithm(multi-modal routing) right ?
>
>     This one looks promising also:
>     http://www.eot.state.ma.us/ developers/
>     <http://www.eot.state.ma.us/developers/>
>
>     This appears to have all the MBTA mass transit schedules in GTFS
>     format for doing multi-modal stuff. And see the Highway section for
>     Massachusetts Planned Roadway Events XML Feed BETA
>
>     Here is another possibility for the sate of Colorado:
>     http://www.cotrip.org/xmlFeed. htm <http://www.cotrip.org/xmlFeed.htm>
>     looks like it would require an agreement to use their feeds, but we
>     can check into that.
>
>
> These are mostly dealing with multimodal trip planning. For time
> dependent routing, we need time dependent road data. I guess not many
> applications have come up in this area since such data is not yet easily
> available for free.
>
>     Anyway these might be a start. I don't have time at the moment to
>     chase any of these down. But it is a starting place.
>
>     -Steve
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>
>
>
> --
> Regards,
> -Jay Mahadeokar
>
>
>
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