Conundrum

Why would someone stick a polling station just fifty yards from another polling station for one single by-election in one single ward, when there is ample room in either polling station to accommodate the other one...and this, by the way, for a town council election with an expected turnout of ...um....20% - tops? (It happened today in the Thatcham Town Council South by-election.)

Answers on a postcard or stuck-down envelope, please....

Update: Simon Dickson has produced an excellent aerial photo here, pointing out the position of the two polling stations.