President and COO Enterprise Holdings 2010 rank: 29 Age: 51
The privately held rental-car company saw its fiscal 2011 revenue jump to more than $14 billion from $12.6 billion. The operations chief now oversees about 7,700 locations globally and
helped expand the rental fleet a record 11% in 2010 and another 11% this past fiscal year.
The list is compiled by FORTUNE editors, who consider four criteria: the size and importance of the womanís business in the global economy, the health and direction of the
business, the arc of the womanís career (resume and runway ahead), and societal and cultural influence.