Dramatically expanding transit and active transportation over the next few decades could reduce carbon emissions from urban transport 40 percent more than following a car-centric trajectory. And it could also save the world economy $100 trillion.
That’s according to a new report presented recently to the United Nations by researchers at UC Davis and the Institute for Transportation and Development Policy [PDF]. The team modeled the cost and greenhouse gas impacts of two scenarios for the future of world transportation up to the year 2050.
The baseline scenario assumes a business-as-usual approach to transportation. Following this path, transit systems across the globe would grow modestly over the next few decades, while driving would grow considerably, especially in developing nations.
Urban transportation produced about 2.3 gigatons of carbon dioxide in 2010, or about a quarter of total transportation emissions. This is expected to double under a business-as-usual approach by 2050.
Following a different path — which the authors call the “high shift” scenario — by 2050, countries around the world develop high-quality transit systems and bikeable, walkable street networks on par with today’s leading cities.
In the “high shift” future of 2050, most countries will have doubled or tripled their total rapid transit capacity. The authors modeled a dramatic increase in urban rail systems and even bigger growth in bus rapid transit systems. In the model, most major cities in the world would have BRT systems as extensive as Bogota’s TransMilenio.
This scenario also assumes more compact walkable development and increases in cycling — particularly e-bikes in developing nations. ”Most cities could achieve something approaching average European cycling levels,” according to the authors, but still below global leaders like the Netherlands. The “high-shift” scenario also projects the effect of widespread road pricing or other financial incentives that favor sustainable modes. As a result, urban vehicle traffic would only reach half the level projected in the business-as-usual scenario.