Dubai Metro success

There was a piece in the paper today talking about ways they are looking to improve the service on the Dubai Metro and talked about its overall success. Undoubtedly, it has carried a lot of passengers, but one paragraph citing its success said...

Mr Al Hammadi said that a study carried out on Sheikh Zayed Road found a reduction in traffic of at least 15 percent [in the period the Metro has been open - two and a half years].

Lies, damned lies and statistics? Has there not been a financial crisis over the last two and a half years? Has not virtually all major construction ground to a halt in Dubai over the last 2 and a half years? Has there not been a population reduction in Dubai as a consequence? Guess why there has a been a 15% traffic reduction?! Anyone who has a car is still driving. Mostly, in my opinion (willing to be proven wrong), people who use the metro do not own a car. I would use it, but it is so sslllloooooowwwww and much quicker to drive on the, now 15% emptier Sheikh Zayed Road!