The rapid motorization of countries like China and India is a scary prospect. China and India alone acheiving the same levels of vehicle miles traveled (VMT) per capita as the United States would probably push us past irrevocable climactic tipping points.  Transportation planners in these countries, meanwhile, already have a nightmare of a task trying to unclog streets, even though driving trips represent a considerably smaller fraction of travel than in the U.S.

Unfortunately, in India at least, politicians overwhelmingly aspire for their country to become a nation of car owners.  The promotion of a domestic auto industry, an interest in mega-construction projects, and a belief that private auto ownership will best provide mobility for its citizenry are all reasons that the government, at all levels, has developed a keen industry in motorization.  Perhaps more importantly, the public – to a large degree – also aspires to own cars.  Trying to argue that Indians should not buy cars is simply not a tenable position right now.

Given this political and social climate, it is encouraging to note that in many cities in the world, relatively high rates of auto ownership do not necessarily mean the demise of public transit.  The plot below, constructed from the Millennium Cities Database, shows public transit mode share vs. private car ownership for 100 prominent cities around the world.  Notably, there are a number of cities that have relatively high rates of car ownership (greater than 200 passenger cars per 1,000 citizens) but where public transit mode shares remain substantial. (Click image below to enlarge.)

This is precisely the sort of evidence that planners and engineers in China and India need to see.  It is possible for public transportation to thrive, even as there are more autos on the road.  The crucial distinctions to be made lie with the cost and ease of car ownership and the quality and availability of substitute options.  In Europe and parts of Asia, even though auto ownership may be widespread, operating costs (notably fuel prices, parking, and in some cities congestion pricing) are higher, parking availability is not as guaranteed, and driving alternatives are more prevalent and competitive with driving.  Households that own cars do not perceive it as the only way of getting around but rather as one option in a menu of choices from which the most appropriate mode for a given trip may be chosen.

This is hopeful for planners and engineers tasked with solving congestion problems (and for citizens of the world concerned with the climate.)  While local planners may find it impossible to stop the rush to motorization, they do have a considerable measure of control over the ease with which cars may be used.  Allocation of road and parking space and provision of alternatives that can compete with or beat private driving in travel time (think: bus rapid transit) are levers that engineers can pull that greatly change the relative ease of driving.

Of course, the struggle does somewhat lie with car ownership itself.  Even if households do not use their car much, they must still park it somewhere.  Furthermore, car owners may not properly assess the personal costs incurred if they have already bought the car (the investment is sunk.)  Nevertheless, there is great cause for hope.  Engineers in China and India and elsewhere have significant power to promote sustainable transportation, even in the face of seemingly inevitable motorization.