It's a dubious title - but can Mexico City claim the crown for a second year running as the most traffic congested city in the world? Well, the title that no city would ever want to win is outlined by the annual Tom Tom Traffic Index. 

Mexico City is among the world's most densely populated cities. So the size of its traffic problem is no real surprise. Many of the Mexican capital's avenues, boulevards and streets are relatively narrow, like they have been since the late 1500s, when Spanish Conquerors first built roads here. Modern-day Mexico City's traffic problem is growing. 

City planners around the world say one of the best ways to reduce traffic congestion in urban centers is to reduce the number of parking spaces.

Mexico City mayor Miguel Mancera, who plans to run for Mexico's presidency in 2018, says he will announce changes to building codes here later this month, aimed at reducing the number of available parking spaces.For now, the annual cost of heavy traffic is estimated at $1.5 billion dollars a year - including loss of productivity -- as drivers in the Mexican capital spend a whopping 66 percent extra travel time -- stalled out in traffic.