In regard to football 'route one' is a direct form of attack in which the ball is kicked high and long towards the goal, in order to stage an attack. In wider use it is a generalized term for any direct no-nonsense means to an end.
'Route one' - the long kick upfield followed by a goalmouth scramble is a common but widely derided footballing tactic. It is often perceived to be employed by teams that are heavy on physicality but light on skill.
The tactic has been used for many years but became prominent enough during the 1980s to be given a name. The Independent, May 1989 included this piece:
"Contrary to the evidence of the top of the Third Division, where Wolves and Sheffield United took route one to promotion, it is possible to escape the lower reaches without resorting to football that makes holes in the ozone layer."
See also: 'back to square one'.