The slowdown isn't automatic, and it isn't for the entire length of the trip.

WSJ: Commuters warned: Summer heat may slow Metro-North

For his new book Gun Guys: A Road Trip, Mr Baum travelled across the US and met a variety of gun owners, from those blasting automatic weapons in the desert to a school teacher hunting pigs.

BBC: Gun control: How a US liberal learned to love guns

The 2013 Nissan LEAF is offered in three well-equipped models, the LEAF S, LEAF SV and LEAF SL. Standard features include a 6-way manual driver's seat, 4-way manual front passenger's seat, trip computer (instant and average energy consumption, driving time, outside temperature and autonomy range), Automatic Temperature Control (ATC), center console storage and 3.6 kW onboard charger.

ENGADGET: Nissan starts US production of 2013 Leaf, vows faster charging and a lower entry price