Massachusetts honors the federal FOPA laws as long as the person is traveling through Massachusetts has a non-residence permit for Massachusetts, otherwise it is a felony. The state also has it's own peaceable journey statute which is very restrictive.
A nick name for the FOPA law. It is a federal law upheld by most (but not all) states. Peaceable journey allows a gun owner to travel through states where they do not have a license to carry, without fear of being arrested. Most states require the firearm be unloaded, in a locked box, or out of the driver's reach when they are in the vehicle. In some states the drivers must pass through the state without stopping, and in others only short stops are tolerated.