The state government should investigate a network-wide cap on charges for Sydney's growing labyrinth of toll roads, an inquiry has recommended.

In the wake of the reintroduction of tolls on a widened section of the M4 motorway, councils in western Sydney have argued a cap is needed to relieve its residents of the burden they bear from tolls compared with people in eastern parts of the city.

The cost of a daily return trip to Sydney Airport for someone living in Sydney's north west is almost $39, compared with about $13 for a resident from the north east, according to an analysis by a transport consultancy firm.

A report by a NSW legislative committee inquiry into tolls, which was tabled in Parliament on Friday, found there was a "disproportionate impact" on residents and businesses in Sydney's west.