It's not ridiculous, Ed, it's to do with the historical development of London's shape. In small village centres, streets naturally narrowed from the wider country roads that led up to them. Land values were (and are) highest in the historical centres, leading people to build very close to the street, often even adding upper storeys that protruded further out into the street than the ground floor. If you wanted to even out the entire course of a street, you'd either have to knock down houses in historic centres or narrow the streets leading up to them.
If you want to read about some of the silly plans that people had for mass motorisation in the 20th century, Google for "Bressey Plan" and "Greater London Plan" (Abercrombie). There were plans to knock down a huge number of houses to widen streets (as happened when the Westway was bulldozed in or when things like the Old Street roundabout were built).
It's not ridiculous, Ed, it's to do with the historical development of London's shape. In small village centres, streets naturally narrowed from the wider country roads that led up to them. Land values were (and are) highest in the historical centres, leading people to build very close to the street, often even adding upper storeys that protruded further out into the street than the ground floor. If you wanted to even out the entire course of a street, you'd either have to knock down houses in historic centres or narrow the streets leading up to them.
If you want to read about some of the silly plans that people had for mass motorisation in the 20th century, Google for "Bressey Plan" and "Greater London Plan" (Abercrombie). There were plans to knock down a huge number of houses to widen streets (as happened when the Westway was bulldozed in or when things like the Old Street roundabout were built).