NSW branch president Neil Wykes has written to new Transport Minister David Elliott pointing to a possible breach of legislation by Transport for NSW, which had extended the consultation/feedback deadline for the Little Hartley to Lithgow section over the Christmas/new year break.

The Little Hartley to Lithgow road widening makes up part of the project to duplicate the highway from Katoomba to Lithgow, which also includes plans for a tunnel under Blackheath and Mount Victoria.

The NSW Government has released designs for the 1.2km duplication at Medlow Bath and that work is expected to start late this year.

Transport for NSW initially released its review of environmental factors (REF) for the western part of the highway upgrade plans (from Little Hartley to Lithgow) in November, with consultation open for four weeks until December 21. This was later extended until January 16.

In writing to Mr Elliott, Mr Wykes pointed out that the Environmental Protection and Assessment Act "explicitly prohibits public exhibition of projects between December 20 and January 10 (inclusive)".

Mr Wykes also noted that the REF was 2500 pages long and was accompanied by 17 technical studies.

"An extension of the Christmas/new year close-down period is both in breach of the Act and is fundamentally opposed to the concepts of equitable and fair community consultation," he said.

"It is a denial of natural justice to have such an unreasonable shortness of exhibition period given the sheer size of the project, volume of material and significance of the places the proposal will impact."

He said these places include the Hartley Valley landscape conservation area, "a cultural landscape with remarkable natural, built and indigenous heritage value recognised by the National Trust 35 years ago and listed on our National Trust register".

The REF canvasses plans to upgrade the 14-kilometre stretch, which would include five new bridges, major reworking of intersections with Jenolan Caves Road and Coxs River Road and an additional lane westbound up River Lett hill.

A Transport for NSW spokeswoman said the timeline for feedback was extended until January 16 to accommodate the community.

The spokeswoman said Transport for NSW has also offered local councils additional time for submissions and would welcome a discussion with the National Trust (NSW).

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