For the first episode of Transit Month on the Total SF podcast, hosts Peter Hartlaub and Heather Knight invited BART's Alicia Trost and Seung Lee, who hold the keys to the transit agency's social media. Trost and Lee talk about BART history, modern challenges and the agency's 50th anniversary celebration, which lands during Transit Month in September. BART's big plans for the birthday include video games at the Powell Station, fare discounts and a big Sept. 10 party at the Lake Merritt Station. Produced by Peter Hartlaub. Music from the Sunset Shipwrecks off their album "Community," Castro Theatre organist David Hegarty and cable car bell-ringing by 8-time champion Byron Cobb. Follow Total SF adventures at www.sfchronicle.com/totalsf  Learn more about your ad choices. Visit megaphone.fm/adchoices