Krabi is a city in southern Thailand.
The main road is quite far from the centre. For 30 Baht you can take some weird kind of public transport to Ao Luek which is about 20 km from Krabi on the national road and makes an excellent hitching spot.
If your driver just passes Krabi, he will drop you on the main road outside of town. But there are a lot of buses that will take you straight to the centre for a few Baht.