require(rgdal)
    require(rgeos)
    library(sp)
    library(raster)
    library(spatialEco)
    library(spdep)

    Shapefile <- readOGR(".","US_place_2000")
    Shapefile <- sp.na.omit(Shapefile, margin=1) # NAs are present for some reason?
    Touching_List <- gTouches(Shapefile, byid = TRUE, returnDense=FALSE)
    # also tried Touching_List <- poly2nb(Shapefile, queen = FALSE)

    all.length.list <- lapply(1:length(Touching_List), function(from) {
if(is.null(Touching_List[[from]]==FALSE){
lines <- rgeos::gIntersection(Shapefile[from,], Shapefile[Touching_List[[from]],], byid = TRUE)
      if (class(lines) == "SpatialCollections") {
        list.Lines <- lapply(1:length(Touching_List[[from]]), function(to) {
          line.single <- rgeos::gIntersection(Shapefile[from,], Shapefile[Touching_List[[from]][to],])
          if (class(line.single) == "SpatialPoints") {
            # Double the point to create a line
            L1 <- rbind(line.single@coords, line.single@coords)
            rownames(L1) <- letters[1:2]
            Sl1 <- Line(L1)
            Lines.single <- Lines(list(Sl1), ID = as.character(to))
          } else if (class(line.single) == "SpatialLines") {
            Lines.single <- line.single@lines[[1]]
            Lines.single@ID <- as.character(to)
          }
          Lines.single
        })
        lines <- SpatialLines(list.Lines)
      }
      l_lines <- sp::SpatialLinesLengths(lines)
      res <- data.frame(origin = from,
                        perimeter = perimeters[from],
                        touching = Touching_List[[from]],
                        t.length = l_lines,
                        t.pc = 100*l_lines/perimeters[from])
      res
    }
})

    all.length.df <- do.call("rbind", all.length.list)