“Let’s get this show on the road” (idiom)

“Let’s get the/this show on the road” or “Let’s put the/this show on the road” means “let’s get started” or “let’s get going.” Theatrical shows often traveled from city to city on extensive road tours. The idiomatic expression usually does not involve an actual show.
 
“Boys, don’t get excited if a girl says, ‘Let’s put the show on the road, sugarpuss, we’re going to a rat race.’ You’re just being invited to a dance” was posted on Woods County Enterprise and Waynoka News (Waynoka, OK) on February 27, 1941. “Let’s get this show on the road with the color test” was printed in the Burlington (VT) Daily News on July 9, 1941. “Let’s Put the Show on the Road!” was printed in the Brooklyn (NY) Eagle on August 24, 1941. “Let’s get this show on the road” was posted on The Enquirer (Cincinnati, OH) on December 6, 1941.
   
   
(Oxford English Dictionary)
colloquial (originally U.S.). to get (also put) the show on the road and variants: to begin a planned activity, esp. after a delay; to get started, to get going. Frequently in let’s get this show on the road. Cf. to keep the show on the road at Phrases P.2e.
1941
Let’s put the show on the road, sugarpuss; we’re going to a rat race.
Daily Texan (University Texas, Austin) 10 April
 
Merriam-Webster Dictionary
get the/this show on the road
phrase
informal
: to begin an activity or journey
Everyone ready? OK, let’s get this show on the road!
 
Newspapers.com
27 February 1941, Woods County Enterprise and Waynoka News (Waynoka, OK), “The Sage Brush - News Of The Waynoka Schools,” pg. 2, col. 1:
Boys, don’t get excited if a girl says, “Let’s put the show on the road, sugarpuss, we’re going to a rat race.” You’re just being invited to a dance.
 
Newspapers.com
2 April 1941, Rutland (VT) Daily Herald, “As She Is Spoke,” pg. 8, col. 2:
It appears from the somewhat startled comments of lexicographers that the gilded youth of precollegiate age is enriching the language. They hear a picturesque product of the swing age say:
 
“Let’s put the show on the road, sugarpuss, we’re going to a rat race.” 
 
Newspapers.com
9 July 1941, Burlington (VT) Daily News, pg. 12, col. 3:
“Let’s get this show on the road with the color test.”
 
Newspapers.com
24 August 1941, Brooklyn (NY) Eagle, pg. A9, col. 2 ad:
Let’s Put the Show on the Road!
(Oppenheim Collins ad, full of student slang.—ed.)
 
Newspapers.com
6 December 1941, The Enquirer (Cincinnati, OH), “Ask Me Another,” pg. 8, col. 4:
... for he is often heard to vociferate, “Five bucks, brother, if you don’t show up at rehearsal” and “Let’s get this show on the road.”
 
Newspapers.com
17 January 1943, Oakland (CA) Tribune, “Navy Blimp Pilot Candidates Learn Free Ballooning at Moffett Field,” pg. A11, col. 2:
“Let’s get this show on the road!” exclaimed Ensign Williams.
 
Newspapers.com
17 November 1943, The Evening Telegram (Superior, WI), “Capt. Bing Is Welcomed,” pg. 2, col. 3:
“Let’s put this show on the road,” he urged, “I’m tired.”