Which series features an army convoy (carrying nuclear stuff?) crawling through narrow country lanes (I think the Brigadier is in it). Which series has giant maggots emerging from the ground?

Thanks Neutronflow. That is very helpful. Can anyone place the one with the slow moving army convoy; I remember it seemed very exciting when I was aged about 8 or 9

That giant magot one was pretty good :) As for the slow moving convoy? well unfortunately that could be any number of episodes... there have been many episodes that may contain something like that. However, I would suggest that it was probably an episode from the Third doctor, Jon Pertwee.