SINGAPORE - In addition to the 80, 000 graves and six farms slated to make way for the Tengah Air Base expansion, a quieter change - in a way befitting the serenity of a heritage road - is the realignment of Lim Chu Kang Road.

Even as agencies study the impact on the 1.8km heritage road and possible mitigation strategies, the move sheds light on the difficulty of preserving "an element of permanence to the landscape", one of the stated aims of the Heritage Road Scheme launched in 2001 by the National Parks Board (NParks).

In March, The Straits Times reported that 10,000 to 13,000 trees could be removed over the next 15 years to make way for transport and housing projects, in a sign of further changes to come.

Including Lim Chu Kang Road, there are currently five such gazetted heritage roads, where a green buffer of 10m on both sides of the road is enforced and the removal of trees or plants prohibited.

Here is a look at what makes each road special as part of Singapore's history.

1. Lim Chu Kang Road

Length of road: 1.8km

Starts at: Junction of Sungei Gedong Road

Ends at: Junction of Ama Keng Road

This is not the first time the historical road has had to move with the times.

Built before the 1900s, stretches of it had been lined with single- and two-storey residences and shop houses, part of a rural idyll that took in the gambier, pepper and rubber plantations in north-western Singapore.

The road itself connected the villages to the city-bound roads of Choa Chu Kang and Bukit Timah, then sheltered by the same angsana, broad leaf mahogany and rubber trees that can still be seen.

Just like how the old attap and zinc-roofed homes disappeared, today the road is once more targeted for modernisation.

When the new 9km road is completed, the existing Lim Chu Kang Road will be closed and traffic diverted to the new one.

But the trees have yet to sigh their last breath. NParks not only stresses that all affected trees will be replaced at least one-for-one, but it is also looking into ways to minimise loss, including the transplant of trees to the new roads.

2.Arcadia Road

Length of road: 918m

Starts at: Junction of Adam Road

Ends at: End of Arcadia Road

Just a short drive away from the bustling city, Arcadia Road preserves more than just a slice of greenery - within view are the old civil service residences of Adam Park Estate, a legacy of Singapore's colonial past.

In hypermodern Singapore, the 918m avenue provides a sense of history and continuity buried in plain sight to the side of the Pan Island Expressway.

With MacRitchie Reservoir just round the corner, here is the optimal area for a calming drive lined by mature raintrees.

Fittingly named Arcadia, it does feel like being in a tiny piece of paradise that Singapore can be proud of.

Related Story Tengah Air Base expansion: Timeline of changes

3. South Buona Vista Road

Length of road: 1km

Starts at: Before junction at Stockport Road

Ends at: Junction of Vigilante Drive

The sharp turns and erstwhile stunning sea views of this descending road is the closest thing Singapore has to the Great Ocean Road.

Today, it is hemmed in by a luscious green tunnel, with a rich diversity of plants on display, including silver backs, acacia, tembusu and tiup tiup.

As with the previous two heritage roads, its value lies also in its historical significance: The Battle of Pasir Panjang, which took place in February 1942, was one of the most significant and fiercely fought battles in the final stages of the Japanese invasion.

It was along the ridges here that the Malay Regiment, led by Lieutenant Adnan Saidi, was defeated.

4. Mount Pleasant Road

Length of road: 1.3km

Starts at: Junction of Denham Road

Ends at: Pan Island Expressway Sliproad

Although not as big as the Choa Chu Kang Cemetery, the hilly slopes along Lornie Road are also covered by graves, and are one of the distinguishing features of this 1.3km pleasant drive.

Along this meandering road, pre-war black-and-white bungalows offer a glimpse into Singapore's colonial era, buildings which have withstood the passage of time.

Fronted by wild sown trees such as cinnamon, palms and figs, they exude a sense of melancholy that one might not expect given the road's name.

Mount Pleasant Road inherited its name from Mount Pleasant, a hill which in the 1860s was the site of the house of a G.H. Brown. It is speculated that part of the estate had been called Bukit Brown after him.

5. Mandai Road

Length of road: 1km

Starts at: Opposite Upper Seletar Reservoir Car Park

Ends at: Junction of Mandai Avenue

Long associated with Singapore's wildlife, Mandai Road also offers a more car-friendly way for visitors to experience nature.

One of Singapore's oldest carriageways , the wide canopies of raintrees frame the speckled sunlight on the relaxing 1km drive from Upper Seletar Reservoir to the junction of Mandai Avenue.

Constructed in 1855, the road served as one of the main connections between agriculture and poultry farming villages such as Bukit Mandai, Sungei Mandai and Nee Soon Village. The road continues to be one of the ways motorists can get to and from Woodlands and Upper Thomson.