A woman rides a public bicycle in Changping district, Beijing, on Nov 11, 2015. [Photo/IC]

BEIJING -- A survey by Beijing transport authorities has found the number of trips in the city by car as a proportion of trips by all mainstream modes of transport has fallen for the first time since the commission began conducting the research in 1986.

In 2014, the fifth year in which the survey was done, 31.5 percent of trips in China's capital were made by car, down from 33.6 percent in 2010, said an official with the Beijing Municipal Commission of Transport on Friday.

The commission also considered subway, bus, bicycle and walking in the calculation.

It put the drop largely down to bus lanes, parking price hikes, Beijing's car plate lottery system and alternate traffic restrictions by car plate numbers on weekdays.

The survey found the average distance covered by each car in 2014 was 15,000 km, 1.5 times the number in London and twice the number in Tokyo.

Under a five-year plan to ease traffic congestion, Beijing has promised to build 1,000 km of suburban railway lines by 2020, and to more than quadruple the total length of bike lines in the city proper to 3,200 km.