Flooding has forced Waihenga Bridge on State Highway 53, near Martinborough, to close overnight.
The NZTA is expecting to provide an update on SH56, also closed, later on Thursday morning.
Further south, roads closed from heavy rain and flooding in Kaikōura are set to reopen later on Thursday.
Torrential rain saw the closure of parts of State Highway 1.
The highway south of Kaikōura is likely to open around 9:30am, however the area between Clarence and Mangamaunu will be reassessed around noon.
The roads were closed due to slips in the area.