Presser...
Metro buses and trucks to distribute water on the freeway. Buses to pick up those that want to get off of the freeways. Not saying where busses will go, though. Ask for volunteers to come to a location to assist in water distribution. Promising fuel to stations along route and fuel trucks to stranded motorists.
Getting late...if you are in the flood prone zones identified get out. If not, stay put because you may get stranded on the road when the storm hits.