What is the fine-grained topic of the following text: The highway, regarded as the biggest engineering project in Borneo, will stretch more than 2,000 kilometres from Teluk Melano in the south-west of Sarawak, close to the Indonesian border, to the north-east through the major towns of Sarawak and end in the town of Serudong in Sabah. Only return the topic.
Construction of a highway in Borneo