Rui Leitao, council's senior roading engineer, told the community board that the national view is that this sort of activity needs to be rated on capital value and not land value.
A report has assessed the impact heavy vehicles will have over the next 25 years and it showed that the current road works programme would fall about $20 million short in keeping roads up their existing condition.
The NZ Transport Agency currently part-funds the roading programme but Mr Leitao said getting extra funding from the agency would need to be backed by strong data.
Mr Leitao said contributions from landowners could be covered off in a bylaw and that's one of the options that will be considered at the workshop.
He said roading authorities across the country were looking at introducing differential or targeted rates to fund maintenance. But the Whanganui council will probably want to have neighbouring councils involved in discussions because not all the timber hauled across the Whanganui road network originates from within the district.
Community board chair David Matthews said another funding option was to levy forest owners a rate of $1.30 per tonne on logs coming off their properties.
"We want to see if legally we can do that. The foresters might be keener on this option than rating them on land use," he said.