Question about constructing a long long path

[Wastoon]

Very nice work! I wonder that how you guys construct a complete divider/centerline on a long path. As the paper says, the BEV feature covers a region of 60mx30m. But a complete way is always long, more than 1km in reality. So how do you construct such a long path in an end-to-end way? Looking forward to your reply, thank u!