The stretch of 160 miles of Interstate 5 served by eight stations marks the next big step in developing an infrastructure that until now has been limited primarily to chargers in homes and workplaces. The stations go from the California border north to the Oregon city of Cottage Grove and are located at gas stations, restaurants and motels just off the nation’s second-busiest interstate. One is at an inn that was once a stage coach stop. Spaced about every 25 miles, the stations allow a Nissan Leaf with a range of about 70 miles to miss one and still make it to the next. Electric car drivers will be able to recharge in about 20 minutes on the fast-chargers. The charge is free for now. The eight new charging stations each have a level 3 charger, and a level 2 charger for backup. Drivers equipped with an electronic key fob can drive up and plug in around the clock. They get the fob when they sign up with AeroVironment’s charging program. Stations can be located with smartphones and software on the cars.