Traffic volumes

[JohnnyPedersen]

Hi there,

I have a couple of questions to you all.

I've been looking on this map for a while:



Now I have commuters data in my region, containing origin and destination of 1000 people biking to work.

How can I make such a grea map like the one above? I tried to google it for a couple of days now, but I don't even know what's that kind of map called. Tried with traffic volume map, traffic flow map, but no help at all.

My idea was to put the data in ArcGis (somehow). Then just add the "From" and "Destination" places as two locations, and give the route unique ID.

So far so good, I got all the routes, but now - how to find out how many people are using a single street segment? In a perfect world, I would be able to extract this info to line attribute, so I could just get one line file with the count on each street.

Anyone?

[JoeBorgione]

What is it you want to map and/or analyze?  Is it traffic volume?  Is it bike routes?  Is it the traffic volume on bike routes? Is it the number of the 1,000 bikers that take the same route?  Or some combination of all?

[JohnnyPedersen]

My fault.

I want to make a map showing the volume of bikers passing through the streets.

I need the amount of bikers passing through an edge (street segment in my case).

Then I want to show it on a map - streets with more than 100 bikers with red, streets with 60 to 100 bikers per day with green and so on.

[JoeBorgione]

And you the actual routes or you're going to model them?

Sorry to keep asking questions.

If you know the routes, like 125 people  go north on a street, then east on b street, south c street and west on d street you could assign some kind of values to those streets.

Modeling would require network analyst, and a good set of roads.

[MelindaMorang]

If you already have the routes on a street network (ie, you used the Network Analyst Route tool on a network dataset), you can use the Copy Traversed Source Features tool to create a feature class of the actual street segments that were traversed by the routes.  You can count the number of times each segment was traversed to get the volume of cyclists on the street.  You can also do some clever things with the dissolve tool to sum existing fields in the routes and such.

[RamB]

Hi,

If you are looking only to map your data (users on each segment), you can use various gradients in size and color to get your result.

If you are looking for a way to model them, unfortunately, ArcGIS network analyst does not have such capabilities (yet) no matter how detailed your network data is (in a true traffic modeling sense, remember users do not strictly use shortest path) and I would not advice you to model this in arcgis, you are better off ArcGIS.

Also, 'copy traversed source features' does not apply to OD matrix, as yet ! 🙂 and to do each route separately ... hmmm.. too much time.
[h=1]kind regards,

[JaySandhu]

Srirama,

You are right that Network Analyst does not provide transportation demand forecasting tools. If that is the goal there I can point to a couple of products that work well with ArcGIS:
Cube from CitiLabs http://www.citilabs.com/
Traffic Analyst from Rapidis  http://www.rapidis.com/

But if the goal is NOT the typical transportation planner type of traffic assignment, then you can simply put everyone on the shortest path (because you do not know if they are all trying to be on the network at the SAME TIME). You can do this by the Route solver mapping the OD pair ID as the routename and solving them all together and then generating the traversal result and summarizing that to find how many times each edge was traveled upon.

And by the way, most planning tools also assume that people travel on the shortest path, but the edge costs are slowed down due to congestion as more and more people are put on the network BUT it is always the shortest path at that time.

Also, if you want the traversal result from OD, then I suggest that you use the Closest Facility solver. It is exactly like OD but keeps track of the edges traveled so that the route geometry can be returned back and traversal result can be generated. But OD and CF are not the ideal tools if you only want to model single OD route pairs. (Yes the OD name can be confusing!)


Regards,
Jay Sandhu