Formula E made a rare trip to a permanent circuit in Portland. Set up outside the city, the track is rural and the walls have disappeared in favour of patches of grass.
The two long straights also made life complex on the battery side: "It's the most complicated circuit we've come across from an energy point of view," said DS Penske's Vergne before the race. "In the simulator, we'd never worked on a track where you had to stay so far back in the pack to conserve energy. With the very high aerodynamic drag of these electric single-seaters, you can easily save 20% of energy per lap by staying behind the leader, and it's clear that apart from pole position there's no point in being the leader before the end."
