Potholes down nearly 40% in three years as LTA ramps up road maintenance
Esther Loi for The Straits Times
The number of potholes found on roads in Singapore has been decreasing over the last three years, with a nearly 40 per cent drop in the January to September period compared with the same period in 2022.
The Land Transport Authority (LTA) attributed the drop to its enhanced pre-emptive maintenance efforts, in a media briefing on Oct 2.
These measures include using road inspection data - obtained from regular inspections and public feedback, as well as analysis of traffic patterns and road types - to plan and prioritise maintenance activities.
As a result, LTA can address surface deterioration in its early stages, preventing potholes from forming and extending the overall lifespan of roads, it said.
At present, the authority conducts inspections on expressways every week, on major roads every two weeks, and on minor roads every eight weeks.
LTA also regularly resurfaces the 9,500 lane-km of roads under its charge: every seven to 10 years for expressways, every 10 to 15 years for major roads, and every 15 to 25 years for minor roads.
The authority said resurfacing efforts have increased fourfold since 2022.
It added that it repairs potholes within 24 hours where the weather permits, and if the road surface is sufficiently dry.
Regular preventive maintenance works help maintain better road conditions more efficiently, while also saving costs in the long term as fewer repairs are needed, said LTA.
In June, the authority adopted a new road maintenance management system for the south-west sector, which allows contractors to respond to road defects more quickly once they receive alerts of issues from road inspections.
The system uses artificial intelligence (AI) and video analytics to conduct road inspections, before mapping out identified road defects to help contractors prioritise and plan their repair works accordingly.
From January to September, 1,887 potholes were detected - 38.8 per cent fewer than in the same period in 2022, 38 per cent fewer than in 2023, and 26.3 per cent fewer than in 2024.
The condition of roads came under the spotlight after a sinkhole appeared in Tanjong Katong Road South on July 26, causing a car and its driver to fall in.
Potholes - defects on road surfaces that can be repaired through patching works - are different from sinkholes, which are more serious structural underground cavities that require extensive engineering works to fix.
To fix potholes and potentially spot sinkholes ahead of time, LTA will continue to roll out new technologies to improve its maintenance of roads.
An upcoming next-generation road pavement study will evaluate various designs and material mixes - comprising materials such as recycled pavement material, warm mix asphalt that can be produced at lower temperatures, and processed plastic waste - to strengthen the durability of roads.
LTA is looking into developing two different sets of designs and materials for different roads - one for expressways, major arterial roads and industrial roads, and another for busy road junctions or bus bays.
This study was initiated in view of the increasingly erratic weather and increased loads on roads partially due to higher adoption of electric vehicles, which are heavier, said LTA.
For example, a mid-size five-seater petrol sedan may weigh about 1,400kg, but an electric vehicle equivalent weighs at least 2,000kg.
The study is expected to start in the first quarter of 2026.
Since November 2024, LTA has also been testing the use of high-modulus asphalt pavement as a material for the supporting layer right under the uppermost asphalt in Defu Avenue 1, which is located within an industrial area where many heavy vehicles pass through.
This is critical, as maintenance works often include sealing cracks, patching potholes and resurfacing the top asphalt layer. Over time, the lower layers may be damaged by water during rainy seasons.
Improving the supporting layer will reduce the need to carry out regular maintenance works on the top asphalt layer.
As the high-modulus asphalt pavement can withstand five times more of the traffic load on existing roads, LTA noted that roads with this new material could have a longer lifespan and require less maintenance.
Repairs of such pavements are faster, with time savings of up to 70 per cent compared with regular pavements.
LTA said that to detect possible sinkholes, it uses data from AI and video analytics to zero in on potential cavities before carrying out more detailed investigations. If necessary, it will then open up the road to check for any abnormal depression and repair it accordingly.
But cases requiring that are not common, it added, as the cavities are usually small, localised points of depression. Sinkholes of the same scale as that in Tanjong Katong Road South are rare.
