Yes — this is not a country where a woman travelling alone has a particular problem. Public safety in China is very good now, and it holds at night as well as in the day. The risks that actually shape a trip out here are the road, the altitude and the weather, and they apply to everyone in the car regardless of who they are.
The short version
China's public safety is genuinely good, and that is the honest answer to the question rather than a diplomatic one. Women travel alone here — on trains, in cities, in the towns along these routes — and it is unremarkable. Violent crime against travellers is rare, and the atmosphere on the street at night is not the tense one people sometimes brace for.
The same ordinary precautions you would take in any city anywhere still apply: watch your bag in a crowded market, don't leave your phone on a café table, use the same judgement about strangers you would use at home. That is not a warning about China. It is just what being a traveller involves.
Where the real risk on this trip sits
Not with people. On the plateau the things that can actually hurt a visitor are the road, the altitude, the weather turning, and the animals — the safety page sets this out in full, and it is the same list for a solo woman as for anyone else. A long drive on a mountain road, gaining height all day, is the part of the itinerary worth respecting.
Which is the same point from the other direction: whether you are alone matters far less here than whether you are rested, hydrated and driving with someone who knows the road.
Practical notes for going solo
Keep your phone charged and a power bank with you; the network thins out between towns. Tell someone where you are going each day, the way you would anywhere. Take the accommodation you would actually enjoy rather than the cheapest room in a village, and if you are arranging a driver, the same care you would take choosing anyone to spend a long day in a car with applies here too.
Beyond that, there is nothing specific to prepare for. The questions people expect to have to ask about travelling alone in this part of the world mostly turn out not to arise.
Questions I get on this one
Is it safe at night?
Is it different in the countryside and the small towns?
What should I actually worry about?
Will I be able to manage without speaking Chinese?
Written from living and working here rather than from a guidebook. This is my own judgement of the place, not a guarantee — as anywhere, your own care is the thing that matters most. Related: is China safe · if you get ill · all essentials