How can I compute density of roads per municipality

[MiguelGomez]

Hi all,

I need to calculate the number of kilometres in each municipality. I have a layer with the municipalities boundaries and another layer with the road maps.

Does anyone know which tool should I use?

thanks,

[MarkBoucher]

Assuming the City name is in the city layer, I would try:

1. intersecting the roads and the city boundaries (Analysis Tools>Overlay>Intersect),


2. open up the attribute table of the created layer,


3. recalculate the shape_length field using the "Calculate Geometry" function, (choose the units you want in the table)


4. select "Reports>Create Report" from table options menu,


5. in the reports wizard choose the city name field first and the shape_length field second,


6. make sure the "Report Field Contents Field" is the same as the city name field.


7. click finish

There are other options that might make the report nicer looking or format it differently, but when I did this I got a what I think you want. I tried it again with a complicated options, but there are a lot of roads in our county and 10 cities, so I'm not waiting for results before I finish this post.

[BKrzyzanowski]

What about if you have 1) interstates, 2) highways, 3) roads, and you want to weigh them differently in the density calculation? Also, for a nationwide computation (multiple areal units), I was considering feature to raster, then using zonal statistics to compute the density measure. The problem is that the vectors of all three road types would be the same size/value unless I select something arbitrarily during the feature to raster conversion. I guess that would be when I assign weighted values. Any better ideas? Appreciate any help and guidance.

[MarkBoucher]

To get density, you can divide the length of road by the city area.

[MiguelGomez]

Thank you very much. It works

Miguel