I had a job at the age of 15, so waiting until I was 18 to get my license would not have worked. It was hard enough getting a ride to work for the 6 months I didn't have a license. There were days I rode my bike (I worked about a mile from home and lived in the country).
At 14 I got my learner's permit and "school permit" which would allow me to drive to school and to school functions (basketball/volleyball practice/games). At 16, full blown license - no probationary period like they have now.