I do have a couple problems with the way the article is written. It calls out NOx as being directly deadly when those in the know blame it for more indirect production of ozone, as some of you have pointed out. There is a certain ratio of VOCs to NOx that will maximize production of ozone (which is the real problem with pollution regulations are attempting to curb), as has also been noted with mention of the weekend effect, where less diesel traffic on weekends dropped NOx output, but made the ratio of VOCs to NOx even more effective at producing O3.
However,
this study points out that a massive drop in NOx output will ultimately have a better effect on slowing ozone reduction than an increase in diesel sales/increase in NOx output, hence the reasoning behind the regulations.
So, this is where the U.S. was smart to not encourage the sale of diesels until they had cleaned up significantly, because diesels have undoubtedly contributed greatly to the pollution problems of places like London and Paris, where for years regulators had provided incentives to buy diesels, thus making their local markets flood with diesel options and ultimately making their pollution issued worse.
But therein lies the rub. Now, since the regulators in Europe have encouraged and incentivized diesel sales for so long, they want to outright BAN diesels altogether from city centers, without taking into account that the latest generation of diesels are in fact exceptionally clean vehicles and are not contributing to the pollution issues like they assume. The older diesel cars with less sophisticated emissions controls devices? Sure, they're contributing to the problem, but the knee-jerk response to ban EVERY vehicle of a certain technology, while ignoring the fact that due to regulations the latest generation are in fact squeaky clean, even the cheaty ones, is disappointingly short-sighted, especially when the blame for most of the problem lies squarely with those very same regulators who thought encouraging the sales of diesels was a good idea more than 20 years ago...
They created the problem and now that diesels have actually gotten very clean, they're going to ban them outright? Fantastic bit of governance there...