London is famous for its red buses and is always trying to improve the bus travelling experience. TFL (Transport for London)is planning real-time bus service information in the coming future.
In London, certain bus routes are good for sightseeing, including 9, 11, 12 and 15, and most services operate from 5 a.m. to 12:30 a.m., with many routes now operating 24-hour services. Buy your ticket before you get on the bus in Zone 1. Look for the ticket machines at the bus stops. You can buy bus tickets from these machines. You may also find it easier and cheaper to buy a Bus Pass or Travel card.
The new Enviro 400 is operating for Metroline (as seen in the picture). The curved front window makes it an ideal bus to view tall buildings such as Clock Tower and the London Eye on route 24.
You may want to try riding the double-decker buses with an open upper deck. These buses have tourist services with live or recorded commentary. You can get off where ever you like, and get on a later bus, as per your convenience. You can get tickets for an all day or multiple days usage.
For further info on routes and fares visit http://www.tfl.gov.uk/buses.