In recent weeks, many flights on the route have been cancelled.
Attempts to close off this route have been only partly successful.
Police stations along the route have been alerted and officers are scouring the tracks for clues.
Passengers on the prestigious London to Edinburgh route have been promised punctuality, good food and clean loos.
Instead of the scheduled 42 minutes from one end of the line to the other, it will take 65 minutes because only a third of traffic lights along the route have been upgraded to give automatic priority to oncoming trains.
Some new construction is taking place, but more than a million square feet of existing offices along the route have been acquired by a single concern: the 26-year-old Davis Companies of Boston and Wilton.
Some 40% of the first phase of construction between London and Birmingham has yet to be assessed and campaigners believe that fewer than half of the sites of ancient woodland along the route have been officially identified so far.
Jalabert's imminent departure has struck a sentimental chord, however, and the verges of the Tour's route have been a forest of placards with one message variously expressed: Don't go, Laurent.
Many of the campsites along the route have been booked up since last year, but there's a host of alternatives popping up for those who weren't so quick off the mark.
On a one-way flight between Sydney and Melbourne, the regular economy fare is $184, at 1.74 Australian dollars to the United States dollar; in recent weeks, seats on that route have been selling for as little as $38.
Away from the UN scheme, 4,200 Syrian nationals who have taken this unofficial route have been granted asylum or humanitarian protection by the UK – prompting refugee groups to ask why the UK doesn't help reduce how many people are exposed to such risk, by increasing the numbers of those eligible for formal resettlement.
