Bukit Lawang is a small village and almost everything is walkable. The main strip of guesthouses, restaurants, and tour operators runs along both banks of the Bohorok River, connected by a couple of suspension bridges. From the centre of the village to the national park entrance is a 20-minute walk.
Ojeks (motorcycle taxis) are available for reaching the bat cave, the tubing drop-off point downstream, or the trailhead for longer walks. Agree the fare before you set off.