I REFER to the Land Transport Authority (LTA) reply last Tuesday, "LTA's approach holistic and balanced", explaining the complications of forecasting vehicle deregistration numbers and how "discrepancies" in vehicle growth are corrected later.
If a forecasting process tries to hit a target and is subject to error, the actual results should fall both above and below the target. But the pattern of vehicle growth rates is quite different. As highlighted in Mr Christopher Tan's original article on Oct 18 ("COE system not working to plan"), vehicle growth rates after 2004 have consistently been above 3 per cent, and much higher than before 2004.
Perhaps the consistent under-forecasting of vehicle growth rates since 2004 was due to systemic errors in the forecasting model. Or it may have been part of a scheme to allow more Singaporeans to own cars, which also removed some pressure from the overcrowded public transport system.
Whatever the reason, the results are massive peak-time overcrowding on the roads, with corresponding parking shortages in HDB and private estates; drops in reported COE revenue, depriving the Government of funds to invest in the transport system; and endless ERP expansions and rate increases, which will not solve overcrowding on the roads unless the daily charge is a significant percentage of the cost of buying a car - hardly a feasible option in the current economic climate.
As the LTA has set the parameters leading to this, on top of scaling back COE issuance and belated improvements to the public transport system, it needs to maximise the carrying capacity of the road network by removing as many choke points as possible. Examples:
Adding lanes to expressways along the whole length of congested sections. If the current widening of the Central Expressway to four lanes is not extended from Ang Mo Kio southbound to Braddell Road and the Pan-Island Expressway, the work now being done will be a great waste of money, merely displacing the jam to the southbound choke point at the Braddell interchange.
Removing arbitrary lane divisions where there are different demand patterns for left and right forks. For instance, with the construction of the underpass at Serangoon Road below the PIE, two lanes lead from Serangoon Road to the westbound PIE and two lanes to Upper Serangoon and MacPherson roads, even though traffic volume is far higher in the latter two lanes - leading to huge tailbacks in the evening. The second lane from the left of Serangoon Road should fork in both directions from the bridge over the Kallang River, instead of being walled off from the Upper Serangoon-MacPherson direction.
Ensuring the timing of successive traffic lights, including pedestrian crossings on straight road sections, is aligned to allow straight-through traffic to flow without interruption.
Examples where this does not happen include the Tomlinson Road junctions with Cuscaden Road and Tanglin Road, and Middle Road from Selegie Road to Beach Road.
Simon Sia
This article was first published in The Straits Times on Nov 4, 2008.
