Istanbul, with its bridges connecting Asia and Europe, has the world's second-worst evening rush hour.
TomTom says a journey that would normally take 30 minutes in free-flowing traffic requires just under an hour during evening peak times.
But that's actually an improvement over the previous year. To help ease traffic, the city has built a rail tunnel under the Bosphorus, and expanded its metro network.
"They've been doing massive investment in new infrastructure," Cohn said.
