Hello. Thanks for mapping here.
About tagging of roads.
Please do not tag through going roads as a track, They will not pick up by NAV systems.  
About tagging of highways
Please read and follow the tagging rules on this linked document.
Decision tree, which tag to be used for roads
https://drive.google.com/file/d/1S48CEVi3yiAYWhIJu57jtLyv0ZVUbGwJ/view?usp=share_link
https://wiki.openstreetmap.org/wiki/East_Africa_Tagging_Guidelines