Civil Defence group controller Neville Reilly said residents would need to take great care in light of the high risk of landslips and hazardous road conditions on the route.
"The wait for uncontrolled access for residents has been frustrating for everyone, but safety has been paramount in all our decision making," he said.
"We want to thank the Hurunui community for their patience and understanding as we have worked together with their Mayor and council through the unprecedented complexities of managing this situation."
He said access was a major milestone for Mt Lyford residents.
It was subject to change because of continuing aftershocks and changing weather conditions.
Geotechnical engineers were continually assessing the route to check the safety of the road and surrounding landslip damage.
With the exception of Mt Lyford residents,
and escorted trips for
deliveries of essential supplies
including farm support, the Inland Rd remains closed to the public so engineering assessments and repairs can continue.
The road has been divided into two based on risk:
Waiau checkpoint to Mt Lyford
• This is lower risk.
• This checkpoint will be controlled by the Hurunui District Council to enable them to manage access for their residents.
• 4WD vehicle is preferred. Some sections will be difficult with a low clearance vehicle/2WD.
Mt Lyford turn-off onwards
• This area is high risk because of road and river conditions and possible landslides.
• A 4WD is essential.
• Access is limited to residents on the Inland Rd and their essential services as well as emergency supplies to Kaikoura.
• There are multiple work sites with control measures. Delays on the route are possible.
• Residents are strongly encouraged to minimise stopping unless directed by road maintenance contractors.
All road users
• Only heavy vehicles to Class One can use the Inland Rd.
• No towing is allowed.
• Check on your insurance status because of the road closure.
•Travel only during daylight hours.
• Carry emergency supplies because of the risk of changes to road conditions. Conditions may change at any time.
To facilitate traffic movements and ongoing road works where possible road users are asked to drive north in the morning and south in the afternoon.