read_shape(file, current.projection = NULL, ...)PROJ.4 character string (see stringsAsFactors, are passed on to readOGRreadOGR. It is possible to set the current projection, if it is undefined in the shape file. If a reprojection is required, use set_projection.
For the Netherlands: often, the Dutch Rijksdriehoekstelsel (Dutch National Grid) projection is provided in the shape file without proper datum shift parameters to wgs84. This functions automatically adds these parameters. See