A St. Patrick’s Day poem is:
   
“May the luck of the Irish
Lead to happiest heights.
And the highway you travel
Be lined with green lights!”
 
Authorship is unknown. The poem was printed in the book By Death Or Divorce ... it Hurts to Lose (1976) by Amy Ross Young.
 
     
Google Books
By Death Or Divorce ... it Hurts to Lose
By Amy Ross Young
Denver, CO: Acćent Books
1976
Pg. 93:
May the luck of the Irish
Lead to happiest heights.
And the highway you travel,
Be lined with GREEN LIGHTS.
 
Newspapers.com
15 March 1985, The Evening Press (Binghamton, NY), pg. 5D, col. 5 classified ad:
May the Luck of the Irish,
Lead to Happiest Heights,
And the highway you travel
Be lined with Green Lights!
   
Google Groups: alt.romance
An Irish Blessing
Patrick E Fleming
3/4/92
May the luck of the Irish
Lead to happiest heights
And the highway you travel
Be lined with green lights!
 
Newspapers.com
17 March 1998, The Star Press (Muncie, IN), “Irish or not, count your blessings this St. Patrick’s Day” by Esther Towns, pg. 3D, col. 6:
“May the luck of the Irish/ Lead to happiest heights/ And the highway you travel/ Be lined with green lights.”
 
Twitter
debzuniverze © ®✌🏽proud Never trumper
@debzuniverse
May the luck of the Irish lead to happiest heights, and the highway you travel be lined with green lights.
9:46 PM · Mar 16, 2009·Twitter Web Client
   
Twitter
Wildflower Team
@WildflowerBread
May the luck of the Irish, lead to happiest heights. And the highway you travel, be lined with green lights. Good nite fab 11!
12:07 AM · Mar 17, 2009·Twitter Web Client
   
Twitter
Mrs. L
@bluka
May the luck of the Irish
Lead to happiest heights
And the highway you travel
Be lined with green lights…
8:10 AM · Mar 17, 2009·Twitter Web Client
   
Twitter
Mike_Conrad
@Mike_Conrad
May the luck of the Irish
Lead to happiest heights
And the highway you travel
Be lined with green lights.
8:18 AM · Mar 17, 2009·Twitter Web Client
   
Google Books
Irish Curses, Blessings, and Toasts:
A Little Book of Wit, Wisdom, and Whimsy
By Nicholas Nigro
Charlottesville, VA: Hampton Roads Publishing Company, Inc.
2018
Pg. 40:
May the luck of the Irish
Lead to happiest heights,
And the highway you travel
Be lined with green lights.
Wherever you go and whatever you do,
May the luck of the Irish be there with you.
 
Twitter
🖕🏻Aunt Crabby calls Bullshit 🖕🏻
@DearAuntCrabby
“May the luck of the Irish
Lead to happiest heights
And the highway you travel
Be lined with green lights.
Wherever you go and whatever you do,
May the luck of the Irish be there with you.”
11:16 AM · Mar 17, 2019·Twitter Web Client
 
Twitter
Halline Ѳ
@_Halline_
“May the luck of the Irish
Lead to happiest heights
And the highway you travel
Be lined with green lights.”
- Irish Blessings ShamrockFlag of Ireland
10:53 AM · Jun 4, 2019·Twitter for iPhone