Kernel Density Tool -- Manipulating AADT Traffic Values for Line Shapefiles

Discussion created by fedakd on May 29, 2012
Conceptually, I understand that kernel density (for my example) takes the value of a line, smooths it out and distributes it to the given search radius using Silverman's equation. The value of the input line equals the value under the curve of the kernel, but I'm wondering how I could manipulate the spread so that the output raster gives the value of the line for the pixels located at the line. If the line value is 1, for instance, how would I get a kernel density output raster whose value is 1 for pixels at the line?

I am using traffic AADT values and would like to stratify my search radii for given road classes (larger search radii for highways, smaller for local roads) to show an increased effect of highways on the adjacent landscape than smaller rural roads. If I increase the search radius to 3000 m, the pixel value at the source is close to but slightly greater than 1/3 of the input value at the line. Is the best way to get an output raster whose values equal the input shapefile simply to multiply it by the search radius (using 3000 m search radius, multiply raster by 3?) Again, this gives me a value slightly larger than the initial value. If I leave the output rasters as is, the increased search radius gives smaller values that are stretched farther out, which is not what I want.

Also, for the purposes of potential publication, is this a defensible approach, or is there a better way to go about this?