In a nutshell, the London buses on routes 25 and 73 will see the TfL test out radar and visual systems which were specially designed in order to alert the drivers of moments when pedestrians and cyclists come too close for comfort to the bus itself, which has its own fair share of blind spots to boot.
This particular trial will make use of the CycleEye and Cycle Safety Shield tools systems, where it boasts of a range of radar and optical trackers which will help monitor wandering things or people that are right beside the buses. The reason that there was a pair of central London routes selected, was due to the fact that these lines will most probably see a higher incidence of ordinary people and cyclists. Hopefully it will undergo a successful trial run in order for more lives to be saved down the road.