On January 31st, 2010, Milan and a few neighbor areas declared a total traffic ban to reduce air pollution. Since such measures are already used in other countries or may be adopted in the coming years, the protests and questions raised in that occasion are useful to think about the real usefulness of traffic bans in general.

On that day, several smaller cities around Milan did not declare traffic bans, many citizens and local administrators publicly declared that traffic bans are simply useless or, at least, discriminatory and proposed in the wrong way to citizens. Others, instead, repeated that pollution caused by car traffic can be greatly reduced with new parking lots, so why don’t build as many as them as possible?

The official reasoning behind traffic bans is extremely simple: “car engines release smog in the air, if we force people to shut them off for a few hours that smog will decrease”. This concept goes hand in hand with the justifications for eco-incentives and ZTLs which are now commonplace in Italy. Eco-incentives are what USA citizens discovered only in 2009 as “Cash for Clunkers”: trade in your old, polluting car when you buy a new, “Euro 5” one, and you’ll get a state-financed discount (Euro 5 is the strictest vehicle emissions standard in Europe).

ZTL means “Zona di Traffico Limitato”, that is Traffic Limited Zone: a city area that only new, “greener” cars can enter. The rationale behind eco-incentives and ZTLs goes like this: “car engines release smog in the air, if we encourage or force people who must or want to drive inside cities to buy an Euro 5 car today and another running on electricity or hydrogen in 2015, that smog will decrease”. Does this make sense? You decide.

Me, I just say that any traffic ban is, at least, an excellent moment to ask yourself something else. A question that, as far as I know, at least during that particular traffic ban in Milan, the powers in charge just ignored here in Italy:

is there enough SPACE or not to park or move so many cars, while still living decently and avoiding huge expenses?

Private cars have huge costs for lots of different reasons, not just because the engines available today pollute a lot. Here’s something I discovered during that traffic ban in a 2008 article: the special machinery and procedures recently introduced to clean the streets of Milan without telling car owners to park somewhere else (but where???) in those moments increased the cost of that service of 40%.

Residents of Italian cities (and of many other cities abroad) know very well that all their streets aren’t big enough to let everybody use a private car without endless traffic jams and that the space to make those streets larger or build enough new ones doesn’t exist, period.

The same residents know very well that this situation would change very, very little even if there were enough money and space to build new parking lots here and there.

Above all, all these citizens know very well, even if they try not to think about it and are strongly encouraged to not think, that this situation would not change at all even if, by magic, all the cars of the world stopped producing smog tomorrow! If that happened, traffic would continue to be as bad as today, no, worse, since there would be no more reason to enforce traffic bans, ZTLs and similar “solutions”. Zero-emission engines would also have no impact at all on all the other costs of private cars, from cleaning the streets (see above) to car accidents.

You can find some other number about how much life and money we waste in traffic jams and problems caused by cars, regardless of their emissions, in this other article. It will help you to ask yourself how much is it worth to build lots of new cars, and where will we put them?