DTC or Delhi Transport Corporation has the largest network of buses in the world, which operate on Compressed Natural Gas or CNG. Delhi became the second city after Pune in the country to operate the system of BRT or Bus Rapid Transit.

In Delhi, India has one of the biggest systems of bus transportation with buses providing 60% of the demand of transport in Delhi, thereby indicating their popularity. Most of these buses belong to DTC, which is state owned and has a maximum number of buses running on CNG in the world, while there are some private operators under Blue-line category and few chartered operators. For all the private operators of buses in Delhi, there has to be an official permit issued by the State Transport Authority. Routes of travel for the buses are well defined points inside the city. Buses have their regular travel points, while there are also special railway routes, feeder routes for metro, outer ring and ring road routes, the last two being counted among the longest routes of buses inside cities in the world.

After Bus Rapid Transit (BRT) system was introduced in Delhi and there were plenty of corridors dedicated to their travel, there has been improvement in the bus services. Currently, DTC is introducing newer buses with air conditioning and low floor buses, where the height of the vehicle floor is about 400 mm from the ground, with a few also having higher floors to move in the streets of the city. It is being planned to revamp the shelters of the buses across the city and introduce GPS tracking in the buses under DTC and in the bus stations, so that there will be real time information on the arrivals of buses.

There was huge uproar among the public in 2007, regarding the increase in road accidents due to the rash driving of the Blue-line buses, as a result of which the government of Delhi concurred to phase out these category buses as per the ruling of High Court of Delhi. In their place, there will be introduction of buses with low floors, which would be under the sole control of DTC. Recently, the government has come up with the decision that this particular process will be done sooner and about 6,600 new buses with low floors will be procured by the transport provider of the city.

It is expected that in Delhi, there were about 8000 buses by the year 2010, with 6000 belonging to DTC, blue line buses would be 2000, low floor buses would be 3125, semi low floor would be 1100 and air conditioned buses would be around 1000. Some of these buses will be equipped with GPS so that they do not stray from their dedicated routes. Presently, there are about 655 buses with low floors in both non-AC and AC categories. The number of routes designated in Delhi is also being increased from existing 357 to 670. By the end of 2009, about 2500 new buses were added to the fleet in Delhi. In total, the city has 17 clusters for buses, each cluster having control by private owners. By September 2008, the first cluster was allotted having 32 routes and these routes will have 270 buses of private ownerships and 295 buses will be of DTC. Each cluster will have the permission to run AC buses to the extent of 20 percent. Alongside, there will be recruitment of more drivers, numbering about 4000 for running these newly acquired buses.

There was a pilot programme by DTC in 2009 November, where smart card system was introduced for the customers to pay their fares and thereafter, the decision was undertaken to have such machines installed in around 10000 buses.