Where we are, each house or pair of house has it's own mini manhole, a little triangular box in the ground near to the garden wall on the pavement where the main ducting runs.
VM usually run a cable from their cabinet down the road and bring it out of the ducting at this point, then make the short run to the house as close to a wall as they can, so it does not get dug up by accident when someone is weeding the garden or whatever.
They wouldn't connect to next door's bit of cable.
Virgin Cable (100/6) + EE Mobile BB