transit transfer penalty

[haiyezhang]

I have build a multimodal network just like the sample which contains street (for peds) and transit network. Two layers have different travel speed.
When I apply the shortest path in this network based on minimum travel time, it seems the best route contains too many transfers. I think it is because the station does not contain transfer penalty.

I was wondering how to realize this penalty function in Arcgis

[JaySandhu]

You can add an attribute value on your transfer stations that will specify the wait time or delay or penalty of taking that transfer. if this will is the same for all transfer stations then you can specify a constant value else you need to add a field to the transfer station attribute table and calculate it to the penalty values. Bring up the properties of the network dataset and for the Attribute tab, click on the evaluators and then select the impedance attribute you are using, and then either map it to the field or change the type to a constant and enter a constant penalty factor.

By the way, you can see how these values were set in the sample Paris dataset, choose the PedestrianTime and look at the Transfer_Stations being set to a field value from a field called Transittim.

Jay Sandhu

[mattlaurie]

I have a follow up to add to this question:

I have a multimodal network with attribute values setup as the wait times.  The problem this has created is that the wait times get included when you first get on at the transfer point as well when it exits.  Since this is a bus network there should only be a wait time when transferring to another bus route, but not if you are transferring from bus to road.

Is there a expression or function to include that would only add the wait time when first getting on a bus, or when transferring from one bus route to the other.

Thank in advance,
Matt

[RobertGarrity]

Hi Matt,

I'm attaching an image showing how you can model the transfer times as you described. Basically, instead of using a single junction to model the transfer, expand it out to be a line (with a junction on each end). The evaluator for one side of the line, e.g. the From-To side, would have a time cost but the other side wouldn't.

Robert

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[ChristopherPollard]

Robert,
What is the best way for me to build/add/digitize a link/transfer to connect a road centerline with a bus route for a multimodal network dataset?
I created my bus routes from the road centerline and I have snapped ALL bus stops to the centerline as well.
Now I'm in the process of adding attributes as well as trying to figure out the best way to build those links/connections.
Do I need to offset my bus routes and stops from my road centerline?
As well as create Fake bus stops that will then be used for "Points to Line" to create that link/transfer?

What is the best way to offset the bus routes as well as stops?

Thanks,
Chris Pollard

[MaximKaskov]

Has anyone found a solution?

[JeremiahNieves]

I have seen others create multi-modal transit networks that utilized the route number as the elevation field so that the bus routes can remain over the street center line. Transfers, from bus to bus, bus to street, or street to bus, then take place "vertically." I am currently working on designing one myself for an accessibility study.

[RamB]

I have seen others create multi-modal transit networks that utilized the route number as the elevation field so that the bus routes can remain over the street center line. Transfers, from bus to bus, bus to street, or street to bus, then take place "vertically." I am currently working on designing one myself for an accessibility study.

The above comment is correct. I started doing such models since 2008, they all work !!!

[RichardLaw1]

What is the best way to offset the bus routes as well as stops?

Thanks,
Chris Pollard

It depends on how you have created your bus route edges. I wrote a Python script that creates bus lines from points, so I simply shifted all of my points by 10m North, checked if any were still coincident, and moved these 10m East. If any were sitll coincident, I could have shifted them again. However I kept a copy of the bus stops as they were when they were coincident with the streets. Then I used the Point to Line tool, using a bus stop ID as a case field: there is now one line between each pair of points. I then ran my Python script to create bus lines, and now my network looks just like the diagram above.

The points coincident with the streets I call 'BusEntrances'. The points offset from the streets, but connected to BusEntrances by a line, I call 'BusStops'. The lines between Stops and Entrances contain a wait time penalty, which you can set different FromTo and ToFrom time penalties for (two fields), representing getting on and getting off a bus, respectively.

However I still don't know how to model tranfers from bus line to bus line, where the lines share stops (both Entrances and Stops), such as along a bus corridor/network spine/major transfer station. Any help?

[MelindaMorang]

Hello everyone.  I just wanted to let you know about a new prototype tool from Esri's Network Analyst team which allows you to add GTFS public transit data directly to a network dataset.  You can use this network dataset with the Network Analyst tools to run time-aware analyses that incorporate the transit schedules.
You can download the toolset and instructions here:
http://www.arcgis.com/home/item.html?id=0fa52a75d9ba4abcad6b88bb6285fae1
Please do not hesitate to contact me at mmorang@esri.com with questions or comments about this toolset.