JHB M2 Freeway - No motorcycles?

[Tjoek]

This morning I had to go to JHB CBD on my GS. Took the M1 South, M2 East, and then Rissik off-ramp. I noticed that the M2 East road signs show that motorcycles are prohibited. Is this really the case, and is this enforced? Can anyone shed some light on this? Do not understand the rationale at all.

???

 

[Veldbrand]

 

[TheBear]

 

[StevedW]

 

[iamgigglz]

 

[TheBear]

 

[Cracker]

 

[Tjoek]

 

[TheBear]

 

[Shaun500]

 

[DeepBass9]

 

[JacoB]

 

[Fudmucker]

 

[spyker]

 

[Swart Gevaar]

 

[McSack]

 

[DirtyTeNeReLess]

 

[McSack]

 

[mox]

 

[DirtyTeNeReLess]