Actually having a private car or the like is very helpful when visiting Hattusa itself. It is a little ways out of the town, though not far and easily walkable if you have the time, so this is not the real issue. It is inside the ruins where having a car is handy if you want to see as much as possible. The ruins are very extensive and very hilly and there is really a lot to see. There is, however, a nice, paved one-way road that makes a circuit through the ruins inside the walls, going right by the major sites, with plenty of good places to stop en route wherever one wants in order to walk around and look at specific areas.
Bogazkale is a fairly short, easy drive from Ankara. From Kizilay itself, in the heart of Ankara, we arrived at Bogazkale in our minivan in just about 2 hours, 45 minutes. The roads are good, especially east of Kirikkale, with a multi-lane divided highway althe way until the turn off to Bogazkale itself, and even then the road is still good.
From Ankara, follow the signs for Samsun, this will take you on the D200-E88 towards Samsun and Corum. Do not head to Yozgat and stay onthe road to Samsun until a luittle passed Sungurlu. Then, there will be a turn off to the right (an overpass and new turn-offs are being built as of Feb.2009), clearl marked with signs for both Bogazkale and Hattusa itself. Take this and it will lead right to Bogazkale.
It is a pleasant, easy road trip through nice countryside. There are a number of towns and plenty of services all along the route. One familiar with Turkey will not be surprised to know that there are gasoline/petrol stations everywhere, sometimes one after another, so one will never be far from one anywhere on the drive. Many of these, as is often the case, also offer food, including et mangal (grilled meat), tea, etc. This is especially true of the area from Nakara through Kirikkale, but even to the east, services are plenty.
Hattusas is situated near modern Bogazkale (formerly Bogazköy) some 150 km east of Ankara in the Province of Çorum, at the northern reaches of the ancient landscape of Cappadocia. A city approximately two by one kilometers in area, situated on the slopes of a high rocky massif (950-1250 m above NN level).
It is only a two and a half hours drive from Ankara and you get a magnificent view of the Anatolian hills. Take the highway 200-E88 out of Ankara and look for signs for Samsun, then turn for Corum driving past Delice and Sungurlu and look for Bogazkoy.
The dolmush from Bogazkale to Sungurlu leaves from the village square when it is full. It costs 1 500 000 TL.
If you are going to Amasya you should ask the driver to be dropped at Mavi Ocak, a restaurant by the road outside Sungurlu. Some buses to Amasya stops here for lunchbreak. I had tea and sat down and waited almost an hour until the next bus came. To Amasya I paid 10 000 000 TL and it took about three hours.
If you from Sungurlu are going to continue to Ankara you should go to the otogar. The Bogazkale dolmush doesn't stop at the otogar, but in the centrum, not too close to the buscompanies offices.
I went with Hattusas buscompany (ticketcounter 37) from Ankara otogar to Sungurlu. It took about 3,5 hours and the ticket was 8 000 000 TL.
Arriving at Sungurlu otogar a taxidriver at once came up to me. He said there were no dolmushes to Bogazkale this time of the day (Saturday afternoon). I tried to ask around and as I asked by a minibus my backpack was allready in the taxi. A women in the minibus said yes when I asked for the dolmush to Bogazkale, the driver said service centrum and told me to take the taxi. Now I now the dolmush for Bogazkale leave from the centrum but I still don't know if there were any that afternoon. What I know is that it felt like the people at the otogar worked togheter to have me taking the taxi.