From Beltway north or south? If they are up in the Humble area trying to leave, it shouldn’t be a problem. From the Beltway south and 59, I don’t know, I’ll see if I can find out and get back to you. (unless someone already responded)
texasx - check here:
http://apps.dot.state.tx.us/travel/road_conditions2.htm
I searched flooded and closed for US59 and nothing showed up. I don’t know if that is realiable or not but it’s the best I could find so far.