http://singaporeseen.stomp.com.sg/singaporeseen/motoring-goondus/driver-swerves-into-car-on-pie-then-speeds-off-like-nothing-happened
It's quite common to have both drivers changing lane at the same time, eg. lane 3 to lane 2 and lane 1 to lane 2 . The above link posted on stomp is a classic example. The driver that change from lane 4 to 3 did not practice defensive driving, and the Cefiro driver that change from lane 2 to lane 3 did not check blindspot and accident happen. So a lesson learn from this is that, Please practice defensive driving and check blindspot when changing lane.