David Hickey looks after public affairs, including end-of-life tyre stewardship for Michelin in Australia and New Zealand, where its tyres arrive through Tyreline Distributors.
He rates Tyrewise as fair and transparent. His caution is about what sits either side of it. “End-of-life management is one small part of the life cycle analysis. It’s an important part, but what we don’t see enough is people talking about what goes into making a tyre, how it’s designed, how long it lasts. The longer the tyre performs, the less waste you have to treat.”
A good recovery scheme, he warns, can become a reason not to look upstream. His example is a European push to lift the legal minimum tread depth from 1.6 to 3 millimetres. “You would not be putting any onus on manufacturers to improve the product.
What could happen is people just put on more rubber.” Millions more tyres a year would arrive for recycling before their time. Michelin’s answer is design: compounds that wear more slowly, regenerative tread patterns, similar performance new to used, lighter tyres that need less processing afterwards and burn less fuel in use.
The first crumb rubber chipseal came this year, on a quarry road Fulton Hogan operates in Selwyn, chosen so the team had total control and no public traffic to manage. Australian colleagues came across to make sure the work followed best practice, and Fulton Hogan adopted the Australian specifications as they stand, since they already allow for the softer bitumen that colder South Island conditions need. The seal is being monitored.
The main change in the last twelve months, Bryan says, is a reliable, consistent, good-quality local supply of crumb. Quality is specific: consistent sizing, compatibility with the bitumen, and no metal, which wears out nozzles and pumps. Locally made crumb could replace up to 16% of the bitumen New Zealand imports.
The benefits are longer seal life, flexibility, less cracking and less flushing in summer, and lower whole-of-life cost despite higher setup costs. The work ahead is research: NZTA currently specifies emulsion seals on state highways because they are sprayed at lower, safer temperatures, while crumb rubber currently needs heat. “If we can get crumb rubber into emulsion, I’ll be very happy…it means operating at a safer working temperature.”