The warning comes from the region’s peak tourist body, Great Ocean Road Regional Tourism (GORRT), which says major public infrastructure is critical to sustain a growing tourism industry.

In its draft 10-year master plan released on Friday, GORRT says successive state governments have allowed the region’s roads and natural attraction to decay from a lack of funding.

“Public safety is also compromised with key assets now substandard or closed due to a lack of maintenance funding,” the plan states.

“Car parks and access roads servicing a number of key locations are totally inadequate, poorly planned and now compromising visitor and pedestrian safety.”

The federal and state governments have committed $50 million over a five-year period to 2019 to address the neglected maintenance of the Great Ocean Road, but GORRT estimates the route will need $20 million every year thereafter to maintain its standard.

“The majority of roadside pull-overs were created decades ago and can no longer accommodate safe parking for travellers seeking a photograph or short walk. Many are poorly maintained and poorly located, requiring an audit of capacity, need and safety.”

The plan urges solutions to improve parking, access and safety at Gibson Steps and coach parking at the Twelve Apostles. It calls for feeder roads and signs to be upgraded and for roadside vegetation, which often blocks ocean views, to be regularly maintained.

“The current condition of national parks’ facilities and infrastructure is sub-standard and failing to meet the expectations of visitors,” the plan states.

“While natural attractions form the core experience for the region and their maintenance remains substandard, increasing length of stay and (visitor) yield will be increasingly difficult to achieve.”

The GORRT master plan is designed to boost the tourist dollar, allowing the industry to support 7600 direct jobs and 5000 indirect jobs by 2020 and become the region’s biggest sector.

Board chairman Wayne Kayler-Thomson said the plan to increase economic return would have flow-on effects for businesses, residents and communities.

“Tourism provides a fantastic opportunity to boost local economies, create employment and enable the region to transition to a sustainable future,” Mr Kayler-Thomson said. He said the plan would require “new levels of regional collaboration and co-operation” if it were to be successful.

The draft plan is open for public comment until June 22. It can be viewed online at greatoceanroadtourism.org.au