For those who have a strong a priori preference for LRT over BRT and are interested in transit, I recommend Jared Walker's book "Human Transit," and his
blog of the same name. It is a great discussion of the basics of transit, and has some really thought-provoking arguments about technology agnosticism, and the need to look at goals before deciding on a technology to use.
To my mind, the main distinguishing characteristics of LRT as opposed to BRT are that some people seem to like it a lot more, and that it is a lot more expensive. The former is not really a characteristic, and I’m tempted to believe that mainly follows from the latter.
Assuming that there is a limit to the amount of money that can be spent on London’s rapid transit system, which there is, choosing LRT means choosing to serve fewer riders and cover less area. LRT may well be the right technology for the areas that need better service, but if it is, the price tag will not be $300 million. And to assume LRT is the right choice because “BRT is just buses” and “people like LRT more” seems rash.
What happens if, with the budget that is politically supportable, you can do BRT on both a 9-kilometre Oxford line and a 15-kilometre Richmond/Wellington line, or LRT on just the first? Would the right choice be LRT, even if it serves half the riders? Ultimately, that’s the choice that’s being made- to serve fewer riders- when a more expensive technology is chosen.