Merging into Traffic

wingssail image-fredrick roswold
Soi 11

Notice that the passenger is riding side saddle? It seems a bit precarious to me but most of the girls riding on the backs of a motorbikes sit this way and they are not hanging onto the rider, so how do they stay on?

When Judy rides on a motorbike, even in a skirt, she rides with a leg on either side.