More than a third of pedestrians have been dubbed "smartphone zombies" after researchers spotted them crossing some of Sydney's busiest streets while distracted by their electronic gadgets.

Researchers for the NRMA monitored more than 26,000 pedestrians as they crossed three CBD intersections and one in Parramatta in April and May.

Distracted pedestrians risk being hit by vehicles while crossing the road, the NRMA has warned. Credit:Christopher Pearce

They found 36 per cent crossed the road while using their smartphone or headphones, 7.5 per cent crossed illegally and 3.4 per cent crossed illegally while using their devices.

About 17 per cent of those who die on NSW roads are pedestrians and more than 1500 are hit by vehicles each year.