Refinements to transport systems in cities worldwide could lead to $70 trillion in savings by 2050, according to a report published on July 10 by the International Energy Agency (IEA).

The study looked at 30 cities around the world and cited Belgrade, Serbia; Seoul, South Korea; and New York City as examples of cities that have saved money by making changes to transport.

Belgrade refurbished its rail system, tripling passenger levels; Seoul passed reforms that took away incentives for bus drivers to carry as many passengers as possible and as a result, ridership, speed and safety all increased; and New York City took 11 minutes off travel times within one year of introducing express bus services, while increasing ridership, the report stated.

If other cities make similar changes, the study suggested that the savings in fuel, time and efficiency could lead to savings and improvements in quality of life that should not be ignored.

By 2050, global urban population is projected to reach 6.3 billion as more people migrate toward urban areas and as urban areas expand geographically.

"We must plan infrastructure, logistics and energy systems now that make sense today and over the coming decades," IEA Executive Director Maria van der Hoeven said in a statement, adding that 70 percent of the world’s population will live in urban areas by 2050.

That other cities should follow suit in making the aforementioned improvements is “urgent,” van der Hoeven said.