hal·cy·on[hal-see-uhn]     

–adjective
 
calm; peaceful; tranquil: halcyon weather.
  
rich; wealthy; prosperous: halcyon times of peace.
  
happy; joyful; carefree: halcyon days of youth.
  
of or pertaining to the halcyon or kingfisher.
 
–noun   

a mythical bird, usually identified with the kingfisher, said to breed about the time of the winter solstice in a nest floating on the sea, and to have the power of charming winds and waves into calmness.  any of various kingfishers, esp. of the genus Halcyon.

 

 Origin:
1350–1400; 

Synonyms- serene, placid, pacific, untroubled.

My addition to the definition: 

A halcyonic adventure-one of curiosity, openness, a willingness to allow whatever comes ones way to just happen
(It’s my blog I can make up a definition if I want to)
 
Highway, well because it’s a road trip and halcyonbyway or halcyonroad didn’t sound nearly as cool as halcyonhighway
 
Take the journey with me, I doubt you’ll be disappointed