The state government is trying to keep crucial studies on Illawarra traffic out of public hands, according to Keira MP Ryan Park.
In June this year, Mr Park lodged a freedom of information request to gain copies of several reports, including the Thirroul to Unanderra Network Strategy and the Lawrence Hargrave Drive Corridor.
In late 2017 Roads and Maritime Services began work on the network strategy only to have it remain unfinished and replaced by the Illawarra Shoalhaven Future Transport Plan.
This change happened on November 2018 and the draft of that plan is yet to be released.
In a government response to Mr Park's freedom of information request, he was told it would cost $345 to access the reports - a standard FOI application costs just $30.
Mr Park suggested the high fee was a way to restrict access to the reports.
"Traffic congestion is only getting worse and the government clearly doesn't want to release the report. They want to keep it under lock and key," Mr Park said.
"While the government and Transport for NSW continue to play games with this important document, the residents continue to suffer in snail-pace congestion."
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Mr Park believed residents and motorists "had a right" to see the Thirroul to Unanderra Network Strategy.
Transport for NSW said the charges levied on Mr Park's application were in line with FOI requests.
In this case, Mr Park was told processing would take an extra seven hours to review the information captured in his request - on top of the five hours already spent on it.
Transport for NSW said the cost could be reduced if Mr Park changed the scope of his enquiry - however he had chosen not to do that.
Transport for NSW said the region's Future Transport Plan was expected to be completed some time next year.