Oslo, Norway plans to be car free by 2020. This will reduce their greenhouse gas emissions by 50% compared to their 1990 levels. 

In order to accomplish a car-free Oslo, they will rely on mass transit (buses, trams) and bicycles. This will include building over 35 miles (56 km) of bicycle lanes by 2019. 

Here's the full article:

https://momentummag.com/oslo-will-be-car-free-by-2020/