Baird pledges high-tech M4 upgrade

Technology upgrades to a 36-kilometre stretch of the M4 in western Sydney will speed peak-hour travel times by 15 minutes, Premier Mike Baird says.

Mr Baird said on Thursday that $395 million in funding was locked in for the upgrade, provided his electricity privatisation plan goes ahead.

He said construction of various technologies, including traffic lights at entry ramps and sensors to smooth traffic flow, would begin in 2017 and wrap up in 2020.

"The package is long overdue," Mr Baird said.

"We have now got the funding and we will deliver it."

He said similar upgrades in Melbourne had reduced accidents and vehicle emissions and improved traffic flow.

The technology will be installed on a stretch between Parramatta and Penrith.