Is it safe to drive alone?

Yes, provided you stick to toll roads (cuotas) where possible, avoid driving after dark, and never pull over to help strangers on the highway.

Do I need to speak Spanish?

It helps, especially in inland towns like Merida. Most people in tourist areas speak English, but a few basic phrases will earn you better service.

Planning a Two-Week Solo Trip Through the Yucatan Peninsula

Fly into Cancun, rent a car, and stick to a loop that balances coastal towns with inland colonial cities and Mayan ruins. Budget for at least $100 per day to cover car rentals, gas, cenote entry fees, and comfortable mid-range accommodation.

Secure a rental car. Public transit exists but will double your travel time. Rent a car at the Cancun airport. Ensure you get full coverage insurance (CDW is mandatory in Mexico) and photograph the car thoroughly before driving off the lot.
Map your loop. Start in Cancun/Puerto Morelos, head inland to Valladolid, move south to Bacalar, travel up the Caribbean coast to Tulum, and return to Cancun. Do not attempt to visit every town; pick four major hubs to avoid spending your trip behind the wheel.
Book stays in the 'Centro'. For solo safety and convenience, book guesthouses or hotels located within the 'Centro' (city center) of towns like Valladolid and Merida. You will be within walking distance of bus stations, markets, and social hubs.
Download offline maps. Cell service is spotty on the highways between Tulum and Bacalar. Download Google Maps for the entire Yucatan Peninsula so you can navigate without data.

Is it safe to drive alone?: Yes, provided you stick to toll roads (cuotas) where possible, avoid driving after dark, and never pull over to help strangers on the highway.
Do I need to speak Spanish?: It helps, especially in inland towns like Merida. Most people in tourist areas speak English, but a few basic phrases will earn you better service.