I used to work in Flight Test at the Park Street end.
I seem to recollect there was some talk of having a railway stop on the line adjoining the airfield that ran down to London. It would have been, probably, quite easy to set up a 'mini' terminal to launch regional aircraft from there.
Can't honestly recall where the story came from but in hindsight it would have probably made good sense - especially for the quiet generation of regional aircraft + bizjets now extant.
Railway sidings sound much more fun for the genteel folk of Radlett Village!