I must admit, I have done both. Myself and a friend hitched quite extensively around Germany, Austria and Switzerland in 1990.
Also when I worked in Clifden in Co Galway it was so remote that public transport was very poor and many people hitched as a way of life.
I have however been very lucky and have met the most interesting people both as a driver and a hitcher.
HOWEVER...... nowadays there appears to be so much more danger in doing this (I'm sure it was there then too, I was just oblivious..... and VERY fortunate) and I don't think I would pick up somebody unless I knew them. And I would shudder to even think of Laura doing it as a young adult.