Going up the left

[Pennine-Paul]

It's in Idaho apparently

 

[fossyant]

Huston, where's that?

Bugger ! You still were not on the bike though

 

[BSRU]

Times I do not go up the left are:

HGV, buses or other large vehicles

Any vehicle that is indicating to turn left

When there is insufficient room

If I am unable to adopt a position where a driver can see me

I would also add, where a side road is approaching, some people will turn and not bother to move that stick thing next to the steering wheel.