1.1. At least we can consider whether classification should change when it intersects roads of the same, or higher class (ie `=primary` Nathan Rd). But this is considering Argyle St routing, not MK Rd alone.
1.2. Tai Kok Tsui (also currently `=tertiary` )doesn't justify `=primary` at the western end.  Tong Mi Rd would be from WKC, or LCKR, which should route via Nathan Rd.  
2. This is not the same situation, as Argyle St eastbound doesn't continue from west of Nathan Rd.  Starting the `=primary` on Argyle St (Sai Yee St; or Sai Yeung Choi St S), or Sai Yee St (MK Rd intersection) doesn't explain it. Therefore it needs to start at Nathan Rd. 
