HI Viskop,
We are also travelling down (for Comrades) this weekend and I expect the roads down to be a bit busy on Friday.
The race is on the old road between PMB and Durban, the only place where people will have issues in on the N3 right in town (Durban) and only until about 9 o'clock Sunday morning.
Sunday afternoon/evening it might be congested in and around PMB as every tries to get beack home or to their hotels.