The crossroads association recalls not simply Yggdrasil but also Hermes, another Mercurial/Odinist figure:

"The Romans too erected altars at crossroads for the festival of Ludi Compitales (held between 17th December and 5th January). Parallels are known from northern India and from Japan, where the god Jizo was considered to be the patron of travellers (Martin Puhvel, 'The mystery of the cross-roads', Folklore Vol 87 1976, II)."

http://www.indigogroup.co.uk/foamycustard/fc009.htm

That article's an excellent overview of liminality, by the way.