After two summers of major inconvenience, traffic flow across the International Bridge will be getting back to normal starting tonight … and not soon enough for those involved in Friday afternoon’s fatal accident.   A second northbound toll gate will finally open tonight … with a third lane to open Wednesday.  The third and fourth southbound lanes are expected to open this fall once the old IBA administration building is demolished. Another new twist will be the phase-out of the Prox card frequent user discount … it’s become obsolete and will be replaced with a new software and pricing structure that will only see a 10% saving for those crossing fewer than 3 times a month.