To be sure, more south county residents thought the commercial jets were quieter than they expected than thought the reverse, but a large majority still don't want a commercial airport built there. And those benefits are, in fact, overwhelming. The past 20 years have seen the emergence in Orange County of California's second Silicon Valley. We know a lot about what it takes to make such economies succeed. Two key factors are research universities and excellent transportation.
Orange County has the former, but is very limited in the latter.
Given the huge projected growth in both air travel and air cargo over the next 20 years, these percentages can do nothing but climb. And that means ever more long-distance truck and car trips to distant airports, fouling the air and congesting the freeways. El Toro airport opponents cite traffic as a reason, but traffic impacts would be much higher if their alternative Millenium plan were adopted. The opponents' only valid argument is noise impacts. To be sure, they greatly overstate their case.