The Rubber Meets The Road Meaning

(idiomatic, with "where" etc.) A place or circumstance at which the implementation of a plan or intent is to be achieved.

Example: Used other than as an idiom: see rubber,‎ meet,‎ road.
1928, How to avoid automobile accidents, page 30:
  Even 500 feet probably wouldn't allow you to brake to a stop, because it's "where the rubber meets the road" that counts.
1957, Max Shulman, Rally 'Round the Flag, Boys!:
  Now we're getting down to where the rubber meets the road.
2002, F. Stevens Redburn, Public policies for distressed communities revisited, page 159:
  It can only be judged "when the rubber meets the road"; when its implementation does or does not produce results.
2007, Dan Miller, 48 Days to the Work You Love, page 85:
  It is in the interview that the rubber meets the road.