Originally Posted by GodOSpoons
The store in Watford Junction is accessable off the Metropolitan Underground line, as well as Silverlink Light Rail. That having been said, you could take the Tube, but to give you an idea of scale:
I live in Watford, as mentioned in another post the Costco is close to the M1 junction 5, it's 3.5 miles from Watford Undergroud Station (Metropolitan Line) and 2.5 miles from Watford Junction Station (Rail), you will need a taxi from either.
To be honest I'm a member at the Watford store, was there last weekend and I've been to a number in the US, I would not waste your time, they are very much the same, except with the current $/£ you will find the UK a lot more expensive..!