ABSTRACT
The fundamental meaning of идти (в/на/к) and ехать (в/на/к) in the present tense is ‘to be on one' way (somewhere, to someone)’ (see sBasic Russian, Unit 26), as in:
Я иду в центр.
‘I'm on my way into town.’ (on foot)
Она идёт к своей подруге.
‘She' on her way to her friend' house.’
Мы едем на дачу.
‘We're on our way to the dacha.’ (not on foot)
Президент в этот момент едет в Kремль.
‘At this moment the president is on his way (being driven) to the Kremlin.’