You would think that ending a traffic restriction would improve journey times, but the sudden termination of Jakarta’s high-occupancy vehicle (HOV) lanes had the opposite effect. To use these lanes drivers required two passengers, but a trade in hiring people bought the lanes to an abrupt end last year. The traffic could spread across all lanes, but journey times and congestion increased. In fact, traffic worsened over the whole network almost immediately. Even on roads with no HOV lanes, at times when the lanes had not operated, delays increased by up to two minutes per km. The US embassy measures air quality from its roof in Jakarta. It is too early to see the changes, but we can be sure that it did not get better.
La #piétonnisation de la rive droite, une mesure juste et pertinente. #Pollution #Transports #Santé #RivesdeSeine https://t.co/N5mKXTWX1j pic.twitter.com/xQTe6UEN3l
— Anne Hidalgo (@Anne_Hidalgo) June 29, 2017
In 1994, a UK government committee found that building new roads did not ease congestion. It studied many schemes, including London’s elevated Westway, which was designed to carry traffic overhead, diverting it from the roads below. Instead it was rapidly filled as people made new journeys that they could not make before. A 2006 study on three English by-passes (Polegate near Eastbourne, Newbury and the M65 round Blackburn) found similar results and anyone who uses London’s M25 can see how adding lanes has been futile.
Can it work the other way round? In Seoul an elevated multi-lane expressway was removed revealing the lost Cheonggyecheon river valley without causing traffic chaos. People changed the way they travelled and the traffic went away. So can we cure our urban transport and air pollution problems by converting main roads into linear parks and cycle ways?
