Hainan coastal highway
The coastal tourism highway is the slow scenic ring: viewpoints, beaches and small towns. The high-speed rail is the fast ring. They are not substitutes for each other.
Driving it
Use it for a day or two of viewpoints, not to race from Haikou to Sanya. The expressway and the rail are faster when the clock matters.
Rent a car only if someone in the group already drives on the right and is comfortable with Chinese road signs. Otherwise hire a driver for the scenic day.
Stops
East-coast pulls include Wanning’s Riyue Bay and the Qionghai shore. Do not promise a sunset at a viewpoint you have not checked the same week; construction and closures happen.
Fuel, meals and a night stop should be booked in a town, not assumed at every lay-by.
Continue exploring Hainan
Open another guide — beaches, visa & entry, or a ready itinerary.