How do I predict the location of sites within a certain distance from different areas?

[MadeleineNilsson1]

I'm trying to predict in which areas there might be undiscovered archaeological sites but I cannot figure out how to do this. I have a background map of a region and I would like to create a map that shows which areas of it are within 1 km of three different types of soil (I have converted these to three separate rasters). Also, I would like it to show different levels of suitability depending on how many of these three types of soil are within 1 km. For example: areas within 1 km of all three soil types coloured red, areas within 1 km of two soil types coloured orange, areas within 1 km of one type of soil coloured yellow and all other areas coloured green. 

I was thinking of using Weighted Overlay, but I'm not sure it will work since all my criteria are equally important. Does anyone have any idea how this could be done? I read about an add-in called Predicitve Analysis Tool that sounded perfect for this, but it's no longer available as far as I can see. 

I have ArcGIS Desktop 10.5, version 10.5.0.6491, License type: Advanced. 

[DanPatterson_Retired]

you could use Euclidean distance to produce your soil types.  If they are equally weighted, there is no real reason to produce one raster for each, just reclass your original map as 'good soil' or 'not' as 1 and 0, then do the distance from there, and query the resultant for distances < 1000 m which will produce another indicator grid representing the good soils and the 1000 zone.  Hopefully you are using projected data to begin with.  There are other options such as using 'combine' should you really need to know which soil-which zone.

[MadeleineNilsson1]

Thank you, your help is much appreciated! This seems like a much easier way to do it than everything I've tried so far. Two of the soil type rasters are extracted from one shapefile and the third one I created from a georeferenced map, but I guess I can combine/merge these three easily enough.