The maximum tolls for cars on the M4 East is $4.27,and $12.81 for trucks.

Ms Prendergast said motorists risked endangering themselves or others if they stopped in a lane,reversed or crossed barriers to avoid the tolls.

"What we can't have is the last-minute lane change,stopping or reversing. Slow down and be aware on approach to these areas,"she said."And don't panic – you just need to continue."

In one incident captured by Nine News cameras at Ashfield,the driver of a Porsche stopped in a lane to the new tunnels before reversing to get back onto Parramatta Road.

The Berejiklian government decided against a month-long toll-free period for the M4 East because it wanted to avoid severe congestion at interchanges and entrances and exits from the new tunnels.

The distance-based tolls for WestConnex are capped at $9.30 for cars.

However,the so-calledescalation rate for WestConnex means the tolls will rise by 4 per cent a year,or the inflation rate,whichever is greater.

The M4 East will be connected by 2023 to twin 7-kilometre tunnels being dug between Haberfield and St Peters. Next year,the $4.3 billion second stage of WestConnex – a duplication of the M5 East from Beverly Hills to a new interchange at St Peters – is scheduled to be opened.