The trains from Urumqi to Kashgar, Urumqi to Lanzhou (and Xi'an, Beijing) are stopping in Turpan. Actually the trainstation is not directly located in Turpna but about 1 hours busdrive away. When I was there (June 2007) trains did not go to Kashgar due to a sandstorm. But in the night, while we were still in the train, we could hear all the frighttrains passing Turpan.
The railway station is located 54km (33 miles) north of Turpan in drab town of Daheyan. Minibuses connect with Turpan's long-distance bus station for ¥7.50 (90¢)
On the website www.travelchinaguide.com you can find the schedule of all trains in English. But do not forget to write the Chinese names: "Turpan" is ok, "Urumqi", too. But Kashgar is "Kashi"
There are many buses giong in all directions from Turpan. We saw a lot of socalled "sleeping busses". This busses have two storeys of beds. They also go in daytime. I think it very uncomfortable to be in such a bus during daytime: you cannot sit and look outside, but have to lie all the time.
The bus station is at Lao Cheng Lu 27 (tel. 0995/852-2325), about 90m (300 ft.) west of the central roundabout. Buses for Urumqi (187km/116 miles; 2 1/2 hr.; ¥25/$3; taxi (Santana) ¥65/$8 per person) leave every half-hour from 7:30am to 8:30pm. There are daily buses for Kuqa (638km/396 miles; 15 hr.; ¥62/$7.70; ¥84/$10 upper berth, ¥97/$12 lower berth) and a sleeper bus for Kashgar (1,385km/859 miles; 26 hr.; ¥171/$21 upper berth, ¥196/$25 lower berth). Both depart at 11am.
The road from Turpan to Kucha (Kuqa) is pretty good. It first passes a gorge through Tianshan Baiyanggou, which looks very spectacular. On the walls of the gorge the sand from Taklamakan Desert builds some dunes. After passing this gorge the road (it is a real highway) passes the city of Korla. When I saw Korla first time in 1992 Korla was a small dirty town. Now Korla is a city like Denver with many modern highrise buildings araising out of the flat desert. This sight was quite a shock for me.
From Urumqi to Turfan we travelled by train. It was not a long journey and I remember the train were a little old fashioned but clean and comfortable. Of course, as a tourist group we travelled in 1st class (no choice, as everything was organized by the Chinese Tourist Agency).
On every compartiment there was a hot water termo, so you could do your own tea there. A man passed every hour or so refilling the hot water for the tea.
As the ground around Turpan is flat and desertic, there were good recent roads everywhere when we went and very little traffic.
I don't know about public transport, as we were in a group and we moved around in a private mini bus.
in Turpan: go to the taxi-stand at the main station. Look for a taxi-driver and ask him how much it costs if he shows you around the great sites for a day. They combine this with more tourist, so don't expect the car, but a mini-van. It is the best way to get around, since the sites are mostly outside Turpan.
Getting here from Dunhuang was not easy. I took a 150 km minibus ride to Liuyuan where I caught a night train that dropped me off at Daheyan at 3:30 AM where I had to find another minibus in pitch black darkness to get to Turfan, 35 kms away.