Must we pay hourly worker for drive to conference?

Q. Recently a nonexempt employee left from work to attend a two-day conference. She left at 2:30 p.m. and arrived at the location at 5:00 p.m. I interpret that we should pay for eight hours since her travel was from the work location and within normal work hours. The next day, she left the conference at 4:15 p.m. and arrived back in town at 7 p.m., but she didn’t stop at the office. Since travel time is outside of normal (8:00 a.m.–4:30 p.m.) work hours, is she paid for travel time or just for work hours attending conference? —M.B., Georgia