San Antonio is one step closer to having rapid transit corridor after federal environmental regulators ruled that VIA Metropolitan Transit’s plans wouldn’t violate pollution standards, transportation authority officials said Wednesday. If constructed, the VIA’s Advanced Rapid Transit (ART) project would be the region’s first rapid transit corridor, connecting San Antonio International Airport to Mission Concepcion south of downtown, they also said. All-electric buses would serve the 12-mile route, ferrying passengers in designated center lanes.