Remember the whole thing is so much interconnected, every wing of business adds up to the giant enterprise, dubai is dreaming off. Just to take a look at things..
Dubai's construction boom would create more and more staying places which would host and assimilate more people. At an avg, any house in the SZR n the surrounding areas would have atleast 2 vehicles, resulting in the increase of traffic. Which they would not controll coz its an income to the License issuing dept. Giving Licenses will never b restricted because the Automobile giants coughup a huge chunk of money in UAE.
And it also results in another major income generating business segment of Dubai, Police. More vehicles - less space - more parking charges - more fines. That keeps the local ethnic groups also content coz it creates more jobs for them.. So it keeps every one happy. Except those who work their ass out to make more and more money. 
 
 