the rubber meets the road

alternative the rubber hits the road

1. idiomaticA place or circumstance at which the implementation of a plan or intent is to be achieved.

   It is in the interview that the rubber meets the road.

   2007, Dan Miller, 48 Days to the Work You Love, page 85

   2 more examples

   Now we're getting down to where the rubber meets the road.

   1957, Max Shulman, Rally 'Round the Flag, Boys!

   It can only be judged "when the rubber meets the road"; when its implementation does or does not produce results.

   2002, F. Stevens Redburn with Terry F. Buss, Public policies for distressed communities revisited, page 159

   Synonyms: the tackies hit the tar

2. Used other than figuratively or idiomatically: see rubber, meet, road.

   Even 500 feet probably wouldn't allow you to brake to a stop, because it's "where the rubber meets the road" that counts.

   1928, How to avoid automobile accidents, page 30