Take another look at the original sentence:

Many road signs warned Tommy of the construction work ahead, he didn't realize that his lane was closed, though, until he mowed down a traffic barricade with the front of his car.

You chose to fix it the correct way:

Many road signs warned Tommy of the construction work ahead. He didn't realize that his lane was closed, though, until he mowed down a traffic barricade with the front of his car.

Many road signs warned Tommy of the construction work ahead is a main clause. He didn't realize is a second main clause. You are always correct when you use a period between the two main clauses that create the comma splice.

Go to the next sentence.

HomeTermsExercises MOOCHandoutsPresentationsVideosRulesAboutShopFeedback