":: If you cannot verify on place the signage, "Street view" from an other online map service can be helpfull."
Unfortunately this isn't good advice; you can't use e.g. Google Street View as it's not licence-compatible. See here:
for more details.
Note that this restriction does _not_ apply to Mapillary - according to http://wiki.openstreetmap.org/wiki/Mapillary "There is special permission to derive data from the photos for contributing to OpenStreetMap. The GPX tracks can be used without restriction".