Ford, Dodge and Chevy all offered 12/15 passenger vans until the mid 2000's. At that time all three stopped offereing them for sale due to safety concerns.
Chevy now only offers an 8 passenger van (about the size of the old 12 passenger), however the same van has a lengthened version for the cargo series which features a streched wheel base.
Sometime around 2008/2009, Ford re-introduced the 15 passenger van once again. However the wheel base is only 6in longer than what the 12 passenger van is. In most cases, in reality, these vans are only 11 or 14 passenger vans due to having front bucket seats up front. I have yet to ever ride in a true 15 passenger van.
Dodge no longer even offers a commercial van.