Multiple car hoistway including car separation control

A separation distance is maintained between a leading elevator car (14) and a trailing elevator car (12) traveling in the same direction in an elevator hoistway (16). A shortest stopping distance (dssl) of the leading elevator car (14) and a normal stopping distance (dnst) of the trailing elevator car (12) are determined. The separation distance (dsep) is controlled such that a difference between the normal stopping distance (dnst) of the trailing elevator car (12) and the shortest stopping distance (dssl) of the leading elevator car (14) is greater than or equal to a threshold distance (dthresh).