Yes! The “Z” you see in the Vehicle Registration Number plates of all the vehicles owned by Andhra Pradesh State Road Transport Corporation (APSRTC), stands for Zahra Begum, mother of the last ruler of Hyderabad State, Mir Osman Ali Khan, Nizam VII.
The Nizam’s State Railway (N.S.R.) was established in the year 1879 but the State’s Road Transport came much later. It was in June 1932 that the Nizam’s Road Transport was established as a wing of N.S.R. with 27 buses and 166 employees. And the Nizam’s Rail Road department came to be known as Nizam’s State Rail and Road Transport Department (N.S.R.R.T.D.). Right from the first vehicle of N.S.R.R.T.D., the vehicle registration numbers contained the letter “Z” in honour of Zahra Begum. From a modest 27 buses in 1932 covering a distance of 450 kms, Nizam’s R.T.D., started operating 500 buses covering a distance of 7200 kms. by 1942, that is within a decade and the rapid growth continued. And on 17th September 1948 when the Nizam handed over his dominion to the Indian Government, one of the agreements he reached with Indian Government was that every bus registration number of the R.T.D. should continue to include the letter “Z”.
Immediately after takeover of Nizam’s Dominion in 1948, the Indian Government merged Nizam’s State Railway with Indian Railways and named it as Central Railway Zone. The Road Transport Department was handed over to the newly formed Hyderabad State Government. This bus transport department continued to be called as R.T.D. until 1958. It was on 11th January 1958 that R.T.D. was renamed as APSRTC. Today APSRTC has over 24,000 buses and other departmental vehicles. The registration number plates of all these vehicles contain the letter “Z”, as you can see in the attached pictures.