Well, the thing is that, the congestion charges, they were introduced first as a trial, so they were introduced in January and then abolished again at the end of July, followed by a referendum, and then they were reintroduced again in 2007, which of course was a wonderful scientific opportunity.
Naknade na zagušenost prometa su prvotno uvedene kao pokus u siječnju, a poslije ukinute u srpnju referendumom, pa opet uvedene 2007. Naravno, to je bila divna prilika za znanstvenike.