Most tourists pass through KB and Seria on their way to BSB from Miri or vice versa. When I asked at the Bus station about a bus to MIRI, the answer was vague. the distance is a very short 17 km but the travel might take between one and two hours because of ferry crossings and also immigration services.
they vaguely told me that there is a bus in the morning and another bus in the evening. Since most bruneians have cars, they just drive over and it takes, they tell me just over half an hour.
the people at the hotel had absolutely no idea about the bus schedules to any where nor where the ferry left for the other side. Bruneians dont need public transportation and filipinos are not going to venture out..
There isn't a great deal of traffic in Kuala Belait. The streets are wide and well-maintained and the town itself is well laid out. I wouldn't have had any qualms about driving here.
There are less than ten taxis servicing the whole of Seria and Kuala Belait, and when they are not between the two or out of town, you can find them at the bus station in either town. A fare within KB should cost you about B$5, whereas if you're heading to Seria, expect to pay $B20. The conversation with the driver on the way there will be all about the increase in fuel prices.
If you are travelling to Kuala Belait from Miri (or heading there afterwards), you will need to cross the Belait river. Water taxis will take you one way for B$0.50 and ply the route from 6am until 9pm. It is also possible to negotiate journeys upriver if you wish.
There is actually a bridge further inland, but the toll is 20 ringgit each way. It's probably only worthwhile to do that if you are travelling to Brunei from Miri by private vehicle or taxi. Even scheduled bus services avoid the toll and drop passengers off for the taxi, arranging for another bus to wait on the other side.
I crossed this river twice and got the same driver each time. He was wearing a Manchester United jersey both times too, which I thought was odd.
The purple one brunei ringitt bus leaves the bus station at Kuala Belair more or less hourly for Seria. where you can connect with the hourly or bi hourly services to BSB, at 6 ringitts fare.