Star Map question on page 168 of Core Rule book

[e24ohm]

Folks:
I am reading about World Creation on pages 168-169; however, I have a silly question. I understand that solid lines on the star map pg:168, are travel and communication links; however, what are the dotted lines that connect 0510 to 0610 and 0601 to 0801?

Thanks.
E

 

[Jeraa]

According to the very bottom of page 169, solid lines are communication routes, while dotted lines are trade routes.