Marianne Karth served as a VISTA Volunteer in the position of Chapter Director of a nursing home patient advocacy organization, Citizens for Better Care, after graduating from college in 1977. Later, after obtaining her Master in Public Health, she worked for a variety of non-profit organizations in program administration before raising and teaching her nine children at home.

The loss of her two youngest daughters, AnnaLeah (17) and Mary (13), due to a truck underride crash on  May 4, 2013, led her into a passionate pursuit of traffic safety advocacy. "I am a truck crash survivor. My daughters were not. We were in the same crash, so what was the difference? Their part of the car went under the truck; mine did not. When I learned that hundreds of people die every year from underride and that it could be prevented, I became a mom on a mission to make truck crashes more survivable."