《新唐书·列传·卷一百四十九》
又因每年有使者来，于是开凿驰道，修建驿站五所，设兵护送使者。
又使者岁至，乃凿道五所，置兵护送。
Because there were envoys coming every year, a driveway was built, five post stations were built, and soldiers were assigned to escort the envoys.