What is the evidence that she was driving north? Her body was found in a lay-by off the A1 and her car in London. There is no evidence that she drove her car to the lay-by or that she was killed there. There is no evidence placing her car outside London.I agree. The hitchhiker theory has never made much sense to me on this basis either, given Janice was travelling north yet her car wound up back in London. I suppose it’s possible in this scenario that the hitchhiker was making some sort of round trip, or that they were pretending to be heading north but in reality were just looking for a victim. But that seems unlikely to me. Especially when you factor in the supposedly foul weather that evening, it doesn’t seem likely that Janice’s killer was hanging around in the dark and the rain on the off chance. We might also have had witness sightings of someone thumbing a lift that night, but if there were any they’ve not been made public.
And as you rightly say, we’re still left with the issue of why she was on the road in the first place, given everything pointed to Janice spending a quiet night alone at her home. Something came up, but what?
More likely IMO, that she was dispatched in a garage or lock-up in the Regents Park area and her body dumped in the lay-by, the A1 being the quickest route out of the city. Her car was then moved from the murder scene to Redhill Street. I would be looking at close associates of the husband living in the Regents Park area or with access to such a facility in that area.