I remember seeing this film on TV when I was a kid and was totally absorbed. I still like this type of old British movie. I think it's the good old-fashioned storyline with lots of suspense that does it for me.
So here we have good old Dermot Walsh minding his own business, taking his family on a trip with the caravan in tow and ending up with a wanted criminal holding them hostage whilst on the move with their trailer. For me, the acting is more than decent and for anyone like me who has a penchant for rather cheaply made, but nonetheless good, black and white British second features of this era, it would be a very decent purchase if only it were available on DVD or VHS (hint, hint).
Yes, it's a pity that - ahem - Amazon don't have a great many of this type of good old British black and white on either DVD or VHS.