Reading KML file into R?

To read a KML with the OGR driver, you give it the file name and the layer name.

Roger's comment is that the layer name is hidden in the KML file, and unless you know how the KML was created you can't infer the layer name from the KML file name.

Looking at your example KML, I can see:

<?xml version="1.0" encoding="utf-8" ?>
<kml xmlns="http://www.opengis.net/kml/2.2">
<Document><Folder><name>x</name>
<Schema name="x" id="x">

Which is telling me the layer name is x, not id, and so:

> foo = readOGR("/tmp/x.kml", "x")
OGR data source with driver: KML 
Source: "/tmp/x.kml", layer: "x"
with 1 features and 2 fields
Feature type: wkbPolygon with 2 dimensions

works nicely.

Now, you can try and get the name by parsing the KML as XML using an R XML parser, or you can maybe try reading it in R as a text file until you find the name tag.

The other approach is to run the command-line ogrinfo program which spits out the layer names of a KML file:

$ ogrinfo /tmp/x.kml 
Had to open data source read-only.
INFO: Open of `/tmp/x.kml'
      using driver `KML' successful.
1: x (Polygon)

here showing there is a polygon layer called x.

If you want to do the alternative way using maptool, this should work:

tkml <- getKMLcoordinates(kmlfile="yourkml.kml", ignoreAltitude=T)
#make polygon
p1 = Polygon(tkml)
#make Polygon class
p2 = Polygons(list(p1), ID = "drivetime")
#make spatial polygons class
p3= SpatialPolygons(list(p2),proj4string=CRS("+init=epsg:4326"))

The key here is you need to go through a couple steps to make spatial polygon class.