As mentioned, there is highway=road which says:
Anything which has been tagged highway=road can basically be any kind of “road” from the smallest footpath to the largest motorway
If you know extra attributes, like surface=asphalt + width=4.0 you mention above, or foot=yes + access=no, you can add that. If you don’t know details, you simply don’t add them.
(Related: Feature Proposal - Voting - highway=scramble)