Sydneysiders whingeing about traffic may have a point, as the Harbour City outranks New York on a global congestion index.

Sydney drivers lose up to 151 hours a year stuck in traffic, according to the international TomTom Traffic Index 2016, making it the most congested city in Australia.

Turkey’s Istanbul took out the global top spot as the city most plagued by traffic, while Kansas City in the US can claim to be the least congested.

• Man shot dead in Sydney
• Sydney CBD linked to four cases of lung infection
• Brothers targeted in Sydney factory shooting: reports

TomTom Asia Pacific vice-president Chris Kearney said traffic could be reduced if drivers took collective measures.

“If even just five per cent of us changed our travel plans, we would improve travel times on our major highways by up to 30 per cent,” he said.

Sydney came in 21st on the global list, with Melbourne coming in 75th as Australia’s second most gridlocked city.

Wollongong on NSW’s south coast is Australia’s most gridlock-free city, narrowly beating out Canberra and Newcastle.

The top five worst cities for traffic in the world, according to the index, are Istanbul, Lodz in Poland, Mexico City, Rio de Janeiro and Moscow.