Possible Clues:

• In Offaly, a new sort of street sign with an arrow
• Individual means 'not reciprocated'
• Like a street with an arrow sign
• Like many parking garage ramps
• It's a matter of course with no return
• "Do Not Enter" relative
• Like some streets and tickets
• Like a relationship with a narcissist
• Only travelling in the same direction
• Offers no return to broadcast from Point on route