​The sequence of traffic lights at 560 intersections across the state will start to alter in changes designed to make pedestrian crossings safer.

The changes will affect motorists turning through an intersection where pedestrians are also entitled to cross.

"It's really that green on green, where there's a green for pedestrians and a green for traffic to turn," said the Roads Minister, Duncan Gay.

About an eighth of the state's traffic lights will be adjusted under the scheme, to cost about $5 million.

At some lights the green turning light for motorists will be delayed for four seconds to allow pedestrians to start to cross.

At others, a flashing orange light will be installed, warning motorists to be alert to pedestrians. And motorists at some intersections will simply see a red light, indicating no turn is allowed.

The changes are being introduced following coronial recommendations in response to two pedestrian fatalities, one at Beecroft in 2012, and another at Alexandria in 2009.

Mr Gay said that the number of pedestrian fatalities had increased by eight to 35 this year when compared with the same period last year.

"It is a dire warning to us," the Minister said.

The co-ordinator general of CBD transport, Marg Prendergast, said about a quarter of the state's fatalities and injuries occurred at signalised intersections.

"A lot of those are due to people disobeying the controls, either pedestrians or vehicles, but there have been a few crashes where there's been a serious crash because both vehicle and pedestrian have a green light," Ms Prendergast said.

The two intersections where fatalities occurred have already been changed.

Mr Gay said the adjustments to traffic lights should not delay traffic through the city.

"Because frankly people should be waiting for pedestrians to cross anyway and if you're not doing that you're not doing the right thing," he said.

Some of the intersections subject to the new light phasing in central Sydney include Pitt Street and Park Street, Castlereagh Street and King Street, Market Street and Sussex Street, and King Street and York Street.