Hi,

So I'm trying to create a cost surface pretty much in line with ESRI's tutorial. I have a DEM for elevation, a .tif for ground cover, and a polyline for hydrological data. I ran slope on the DEM and then reclassified it along a 1-10 scale. It seems fine to me:

Then I took my .tif and also reclassed it along a 1-10 scale. It also seems fine:

I took the polyline and turned it into a raster. I then reclassified it into "4" for the lines (because I want them to have a moderate cost) and "NODATA" for everything else. It's not much to look at but that doesn't matter at this point:

But when I go to weighted overlay and try to run these things together, the result is a bunch of squares and rectangles that patchily follow the line raster, as can be seen here. (The lines themselves are from the other reclassified layer).

So somewhere I probably made a basic mistake, and it likely has something to do with that polyline->raster transformation and its integration here. Does anyone have any idea what might be wrong, and could point me towards some information on how to fix it? Thanks for your time.

What is the cost of travelling along the road vs open space?

You are dealing with multiplication so it would be zero for the non-road areas.

If travelling along the road has a 'cost' of 1 (ie easy) but it is 10x more difficult to travel in open space, then the non-road areas should have a cost of 10

Cost path/cost distance needs to consider how the total costs of the components are put together. Multiplication is different than addition. If you are accumulating your costs through addition, then a cost of 0 has no effect on the total. If you are multiplying any of your factors, then things are going to be quite different