If it helps to visualize the difference, here are a couple of pics of local HV lines here in England.

The first is 11kV, so phase-to-ground will be about 6.4kV:
[Linked Image]

The second is a 33kV line which, as Scott said, will actually be around 19kV phase to ground:
[Linked Image]

There's quite a difference in size just between these two types of insulators, so a line at 33 to 40kV to ground would be quite substantial.

We have some 66kV transmission lines (~38kV to ground) here, but none nearby so I don't have any photos, but the insulator stacks are pretty large.