in 1933, the london passenger transport board (lptb) was formed. they took over the london county council trams. soon after this takeover, the lptb decided to replace all of the trams in london with "more modern vehicles". the abandonment programme began in 1935. the trams in the south-west, west, north-west, north and east london were mostly replaced with trolleybuses. this programme carried on quickly until 1940. in 1940, the last tram conversion took place before the second world war. this left only the south london trams and subway routes 31, 33 and 35 running. the subway routes were the only trams to run into north london during the war.