Jitneys started in about 1914, and the Sampan in 1922.
Truth is the same no matter where you find it, and in 1922, the cost of a taxi was obviously too much, and a Hilo taxi driver by the name of Fukumatsu Kusumoto wanted to provide lower, cost-effect means of public transportation for Big Island residents and visitors, mainly Hilo wharf and it’s surrounding areas.
He hit up several of his taxi driving friends, but no one was interested in his idea. Single handed, he was able to obtain enough funding and constructed the first sampan converting a Ford Model T into a multi-passenger jitney back in 1922.
Vehicle modifications started just behind the drivers seat, the back was rebuilt with wooden seats along both sides on an extended frame. Mr. Kusumoto’s single venture brought instant success as the owner of the Hilo Sampan Company. the Sampan Bus became a big hit with sugar plantation workers and their families.
In the 1930s and 1940s there were over 200 Sampans running routes around the Big Island of Hawaii, most casually cruising to pick up riders, and just like Uber or Lyft, delivering them where they wanted to go, picking up other riders along the way
There is one in San Diego that I've ran across through the years, http://justacarguy.blogspot.com/2015/09/this-might-be-only-vehicle-ive-posted-3.html