Betcha Never Knew This!
Never mind, Keefieboy is here to explain it all to you. E-Routes are Emirates Routes, yer basic motorway/freeway thang. D-Routes are Dubai Routes, the main arterial roads. Exits from E-Routes are numbered according to how far they are from the origin point of the route within Dubai Emirate. (Yes, I'm beginning to lose it too). E11 starts at the Abu Dhabi border. The other E-Routes in Dubai all originate from the E11, whatever that is.
Where did I find this cornucopia of infoboozlement? Dubai Municipality's Maps website: you can download PDFs of various maps and documents, some of them fairly esoteric. Like the one showing locations of Chinese, Italian and Pakistani restaurants. Or the one that shows you where all the Indian, Lebanese and American restaurants are.
Oh, and have a look at the 2003 Urban Structure Plan.This seems to have been prepared in 2001: it shows the Palms Jebel Ali and Jumeirah, but not the Deira one. The World and Dubailand are conspicuous by their absence.