MANY more bus commuters and drivers are now able to get to work and home on time since more electronic road pricing (ERP) gantries came up in the city centre and expressways, said Transport Minister Raymond Lim on Tuesday.

While he acknowledged that the ERP has affected the travel patterns of those who choose to go home later in order to avoid the evening ERP on the Central Expressway (CTE), for example, he said many others who were previously unable to get home early at all because of traffic jams can now to do so if they wish.

They can also plan ahead with "a much higher degree off certainty because of ERP," he said in Parliament, in response to questions from Ms Irene Ng, MP for Tampines GRC, who had asked for an assessment on the social and economic impact of raising the ERP gantries and hours on work patterns, businesses and family life.

The Minister said after the gantry on the CTE before the Pan Island Expressway IE exit was implemented in November 2007, traffic volume between 6pm and 7pm fell by about 700 vehicles.

But traffic speeds for the remaining 7,000 vehicles that continued to use CTE increased from 34kph to 50kph.

"So perhaps 700 drivers were affected in some way because of ERP, but 7,000 drivers now enjoy the benefit of a smoother and more predictable commute home," he said.

"If we do not have ERP to deal with congestion, then motorists, and even larger numbers of bus commuters, will get stuck in traffic jams, spend a long time on the road getting to work, and not be able to get home on time. This is hardly conducive to work and family life.

"By having ERP, we can be assured that commuters will get to their destinations on time, and give commuters a choice, rather than leaving everyone with no choice but to endure the daily grind of gridlocked traffic."

On the impact on businesses, he said it was not possible to determine conclusively to what extent the ERP has affected them.

For example, businesses could be affected by economic conditions, consumer confidence and even the weather.

"So while retailers within ERP zones have given feedback that ERP is one of the reasons their businesses have been affected, they also recognise that their business outside ERP hours has also been poor. Retailers elsewhere outside the ERP zones have also reported reduced business in recent months," he told the House.

Mr Lim cited a study carried out by te Land Transport Authority (LTA) to assess the impact on retail sales in Orchard Road after the ERP was implemented on Saturdays and extended to 8pm on weekdays in October 2005.

The study showed that the e retail business in the area improved after the ERP expansion than before.

"Retail sales had grown by about 4 per cent in the year before ERP was expanded. In the year after ERP expansion, retail sales grew by 9 per cent, more than twice the growth a year ago," said Mr Lim.

"This compares more favorably with businesses outside of the CBD, where the growth in retail sales had remained more or less the same over the same period in question.

"So the findings in this particular study of the impact of ERP on retail sales would suggest that ERP, contrary to popular belief, has a positive effect on businesses."

The study mirrored the experience in London, where a similar study on the congestion pricing system there showed that business became better after congestion pricing was introduced compared to before, added Mr Lim.

The minister also reiterated that the ERP was not a revenue-generating measure but was put in place to manage traffic congestion.

'You have to look at the facts. Since we implemented the ERP in 1998, we brought down the vehicle ownership taxes. If you look at say, before the latest round of ERP changes, the forgone revenue on an annual basis for the Government is about $1.2 billion every year," he explained.

"And against that, the ERP revenue collected was $100 million. As I have said before, if motorists were to drive less, the Government will be happy to collect less. So, it is really a congestion measure."