Does anyone know why the HOV is closed?

Hello! So I just got out of downtown and was trying to take the HOV to go home with my friends (we all live in spring and car pool to work or school since we all study or work in the same area) only to find it closed. I tried the Louisiana st. Entrance, it was closed, I tried the Travis St. entrance.. also closed. Any idea why? Cause sitting in I-45 traffic sucks