The best arguement is that Amsterdam is not London.
That is we don't have a circular medieval street plan built around a canal network. It's also a very compact city.
Oh , and that there are large motor ways that take cars out of Amsterdam
So lets not obsess with Amsterdam as the soloution...
We need , borrowing from the Dutch or the Danish, city specific soloutions. So what would work in a N American city grid system may not transfer well to London's sprawl. Paris might be a better comparision?
This was my main concern about the LCC's Go Dutch campaign at launch - how can we attempt to (and why would we want to?) mimic the Netherlands or any other place? By all means, let's take on board what works in other cities but we have to create solutions that are specific for London. I think the LCC campaign has evolved to reflect this commonly held view.