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Updated 25 June 2020

In winter snow and ice road conditions, we advise all road users to prepare for 'chains essential' when travelling on SH73 through Canterbury/West Coast Alpine Pass areas. 

Drivers need to be aware of the following:  

  • If you are travelling in the area, chains should be carried along with blankets, warm clothes, food and water, so if you are caught in deteriorating conditions, you are well prepared.
  • When ‘chains essential’ is operating checkpoints will be located at the eastern and western ends of the ‘chains essential’ area/s, where vehicles will be checked that they are carrying chains.
  • Vehicles without chains will be advised to wait until driving conditions improve and ‘chains essential’ is lifted or advised to use an alternative route.
  • Road crews will not offer chain fitting assistance. Vehicles with poorly fitted chains must not travel under ‘chains essential’ and will be required to wait for the road to re-open to all vehicles or use an alternative route.
  • If a vehicle is blocking the road or affecting road access and compromising safety, crews will remove the vehicle out of harm’s way and check to see if they need assistance.
  • In which case, the road user will be responsible for organising a commercial operator to recover their vehicle. This may result in a short road closure.
  • When the route is posted as ‘chains essential’ SH73 is closed to all vehicles towing g. trucks with trailers, or light vehicles towing trailers or caravans.
  • The road will only close when conditions become too unsafe for all road users to (Our existing arrangements with essential and emergency services remain).
  • Selwyn District Council advises that when Porters Pass is closed, the road block will be located west of Lake Lyndon Road as this road will also be closed for safety.

As conditions can deteriorate very quickly on the Alpine routes, we strongly recommend that motorists check weather forecasts and drive to the conditions at all times.

Alpine residents with questions are encouraged to contact us. Please email for more information.

Frequently asked questions about SH73 winter maintenance [PDF, 130 KB]


SH73 data from the road traffic crash database [XLSX, 3.3 MB]

West Coast winter summary report 2019 [PDF, 4.4 MB]

North Canterbury winter services report 2019 [PDF, 4.5 MB]