Safest ride to IAH?

I'm traveling in 2 weeks and looking to figure out the safest, and most affordable way to get to the airport. I'll be gone for a while, so parking at iah may add up quickly. Being a female traveling alone, I've had my fair share of negative uber rides, especially at 5 AM (when I need to leave for the airport)

Any thoughts on affordable, safer ways to get there? I looked into ALTO, but they don't start driving until 6 AM.