This event sounds interesting. I was informed about it from Bob Gillespie:
Coming up this August is the "One Gallon Challenge", an event where drivers can choose to leave from two locations, Plymouth or Greenfield and then all converge at city hall plaza in the Boston area, at an environmental Festival. A distance of 111 miles.
The event is going to start Thursday, Aug 16 and the rules for the drivers are right here
Boston GreenFest 2012 ~ One Gallon Challenge.
Mike