SINGAPORE - A frustrated motorist's attempt to overtake a motorcyclist who was travelling on the rightmost lane of an expressway sparked off a series of dangerous manoeuvres including tailgating, straddling lanes and weaving in and out of evening peak hour traffic.

On Thursday (May 25), the driver, Chia Hyong Gyee, 61, was sentenced to a week's jail for dangerous driving after prosecutors appealed against his initial sentence of the maximum $3,000 fine. His driving ban was also doubled to two years.

In allowing the prosecution's appeal for a heavier sentence, High Court judge See Kee Oon noted that the motorcyclist himself "was not exactly a model of graciousness on the road" and may have ridden his bike in a "somewhat provocative fashion".

But this did not excuse Chia's reaction, said Justice See, agreeing with prosecutors that the driver was a "road bully who used his vehicle to give vent to his frustrations".

"This was an appalling manifestation of road rage that went beyond rashness or recklessness... A fine would not suffice to signal the need for effective deterrence of such conduct on the roads," he said.

The incident, which lasted for 2½ minutes, took place at about 6.10pm along the Pan Island Expressway (PIE) towards Changi Airport, and was captured on the front and rear cameras mounted on the motorcycle of 44-year-old Aw Seng Poh.

After driving closely behind Mr Aw for some time, Chia moved to the second lane and tried to cut into the motorcyclist's path, without signalling.

The motorcyclist swerved right to avoid a collision and sounded his horn at Chia.

Chia sounded his horn in response and dropped back to the first lane behind the bike.

Mr Aw sped up but Chia accelerated and swerved in and out of traffic without signalling until he caught up with Mr Aw.

While sounding his horn, Chia again tried to overtake Mr Aw from the left but was blocked by a van.

After he passed the van, Chia drove very closely to Mr Aw's bike, with his car straddling the first and second lanes. After passing the bike, he continued on the second lane until the traffic ahead had come to standstill.

When the traffic moved off, Chia remained stationary for about five seconds, to prevent Mr Aw, who had stopped his bike behind Chia's car, from going forward.

Mr Aw tried to move into the first lane but Chia swerved abruptly to block his path.

He eventually rode off, leaving Chia, who was stuck in heavy traffic, behind. Mr Aw made a police report the next day.

In December last year, Chia was sentenced to the maximum $3,000 fine and a one-year driving ban after he pleaded guilty to a charge of dangerous driving.

On Thursday, Deputy Public Prosecutor Francis Ng argued that the sentence was too light, contending that this was "quintessentially a road rage case".

The DPP argued that Chia deliberately used his car to intimidate, bully and endanger the life of the motorcyclist, who was on a much smaller vehicle.

He noted that the video footage showed other vehicles having to get out of the way of Chia's "single-minded pursuit" of Mr Aw for over 2km. Chia's "loutish driving behaviour" is more egregious than the typical road rage punch-up, said the DPP.

Chia's lawyer, Mr Daniel Chia, disagreed that this was a road rage case, arguing that his client had no intention to intimidate the motorcyclist.