Why night pruning got the chop

Trial didn't go well; NParks says daylight needed for pruning & steps taken to ease traffic jams
Jamie Ee Wen Wei, Straits Times 27 Dec 09;

When civil servant Fong Ying Yi sees workmen pruning trees along the roads in the day, she often wonders why it cannot be done at night instead.

'It can be quite inconvenient because all the cars will start to slow down to get out of the lane. It's only when you drive closer that you realise there's tree pruning going on,' said the 25-year-old, who has been driving for about five years.

Tree pruning has been a sore point among motorists, several of whom have voiced their frustrations in the press recently.

They want it to be done at night to reduce traffic jams along expressways and major roads.

The discussion was sparked by a column written by former Straits Times editor Leslie Fong, who raised the idea of night pruning after being caught in slow traffic along the Pan-Island Expressway as a result of some plant pruning.

The National Parks Board (NParks), which takes care of most of the trees along expressways and major roads, said it had in fact considered night pruning.

Eight months ago, it tested the idea along Orchard Road but the trial did not go well.

Mr Simon Longman, NParks' director of streetscape, said workers found it difficult to distinguish dead or diseased branches in the inner crown of trees even though strong lighting was used during the night operation.

The glare and shadows cast by the lighting added to the difficulty of cutting the correct branch.

As a result, the pruning operation had to be repeated in the day to ensure that all dead and diseased branches were removed.

Then, there was also the issue of noise generated by chainsaws which would exceed the permitted noise level for residential areas at night.

Contractors are given small windows by the Land Transport Authority (LTA) - usually two to three hours daily - along busy roads like the Central Expressway, Ayer Rajah Expressway and Orchard Road to prune trees.

'They usually don't block the roads for long,' said Mr Longman.

Each tree requires at least 30 minutes to prune.

Trees along expressways and heritage roads - where mature trees and greenery are preserved and protected - are inspected at least once every 12 months. For trees along major roads or in parkland, it is at least once every 18 months.

The NParks has 11 contractors - each with four to five teams of between three and six men - that help it maintain trees and plants islandwide. Their task is to spot and remove branches likely to snap or are diseased.

Mr Longman said the board's contractors avoid peak hours on weekday mornings and evenings.

In the Orchard Road belt, for instance, pruning is done after 9.30am and must be completed before the lunch hour.

Each year, the board also reviews the time windows with the LTA to ensure that traffic congestion caused by pruning operations is minimised.

Contractors are also instructed to stop pruning when they see traffic building up along the roads.

Pruning operations are typically contained within a single lane, with a portion of it closed so the removed branches can be dropped safely. Vehicles can still move along the other lanes, Mr Longman said.

He added that the board is constantly improving its operational practices, such as using better technology, and training and certifying its workers to shorten the pruning time, thus minimising traffic congestion.

Through its tree inspection regime, the board has sustained the annual rate of fallen trees and tree branches at a low level for the last five years - 62 per cent below the levels in year 2000.

'Pruning operations may slow down traffic but there are tremendous benefits. Snap branches are reduced and as a result, serious accidents are avoided,' said Mr Longman.

At least some road users agree.

Medical officer Charmaine Tang, 25, said: 'It's important that the works go on for the sake of beautifying Singapore's roads and for safety too. Can you imagine if a branch falls on my car in the middle of the expressway?'