Visualising Singapore’s Longest Bus Routes

A data story for HASS02.546: Interactive Data Visualisation

The roots of this data story came from my interviews with residents in the soon-to-be demolished neighbourhood of Tanglin Halt. When I asked them what they’d miss most about the place, a surprising number mentioned the area’s bus connections as a main selling point. There are few feeder buses in the old neighbourhoods lining Singapore’s south-west coast—unlike the new towns, most bus services ply long lines straight to the city centre or across the island, with the end result being that you don’t have to live near a train station to get to anywhere worth going. I immediately thought of the services that ran past my house and how they always took you back from the furthest places. Like them or not, long bus rides are a crucial part of our public transport network, serving all sorts of niche populations like the change-resistant elderly and the unfortunate young partygoer who’s 10 train stops away from home after midnight and can’t afford a Grab.

Where are these long bus rides? On a map of all bus stops, these services are visible as faint orange stripes leading to the dark brown hub of the central business district. The persistence of such routes runs contrary to the Land Transport Authority’s planning doctrine, where the hub-and-spoke model of transport planning dominates the integration of newer, shorter feeder services with the rail network. When mapped out like this, Singapore’s trunk routes appear a faint anachronism of an older, bus-dominated public transport landscape atop the backbones of colonial-era roads.

There is, however, little-to-no documentation on what constitutes a ‘long’ bus ride. Then-Second Minister for Transport Lim Hwee Hua explained in a 2010 Parliament session that a route length of 20–37 km could be viewed as excessive by some. She also mentioned that the LTA does phase out trunk routes when it’s clear that most of its users don’t travel on it for the full length. It can, and it has: during this March’s budget debate, Aljunied MP Gerald Giam raised the issue of the shortening of long bus routes from his constituency to the CBD, which inconvenienced a bunch of older residents. And just two years earlier, Bukit Panjang MP Liang Eng Hwa also expressed some pretty strong disappointment at the withdrawal of long bus services in his constituency following the opening of the Downtown Line. Is this the beginning of the end for trunk routes?

According to the data, probably not.

Looking at the 554 bus routes provided by LTA’s DataMall, it’s surprising just how many of them fit—or even exceed—Lim Hwee Hwa’s benchmark of 20–37 km. The longest service by distance between first and last stops is Tower Transit’s 858 service, covering a staggering total of 73.4 km over 75 stops. Many of these longest routes are also old ones, if the prevalence of two-digit numbers among the top 20 is anything to go by. Several of them are special services. Route numbers in the 500s are specific long-distance routes operated by private companies directly to the CBD; while routes containing an ‘N’ are night services operating from 11pm–2am.

Note: A lot of these routes go by highways, which results in weird jagged lines when rendered in this map. The DataMall API only allows us to query bus routes by their individual stops, not the path they take.

What about by number of stops? From the overlay, we find that most of these longest routes pass through the CBD. This fits the pattern of Singapore’s longest bus routes being older routes designed around the city centre, producing the darker orange bands of frequently-trafficked bus stops that we saw in the first map. It’s important to note that the number of stops shown here might be misleading—bus number 51, for instance, is actually a loop service with around 90 stops between each terminal. According to TransitLink’s website, this journey can take you as little as 2-and-a-half hours—just enough time to finish watching Avengers: Endgame from beginning to end.

Here’s an interactive version of the inset map so you can see where your favourite routes are:

How many of these routes are ‘too long’? A histogram can help us see the distribution of route lengths more clearly.

Histogram of route lengths

Both distributions of route lengths are pretty positively-skewed. Interestingly, both distributions are somewhat bimodal—numerically distinguishing between trunk routes and feeder routes! From this, we might estimate that trunk routes are not exactly being outnumbered by newfangled feeders; on the contrary, they’re more or less equal. At time of writing, we may conclude that the long bus ride isn’t in danger of disappearing.

Another interesting feature is the spike in number of services around the mean route distance of 17 kilometres. Is this evidence of deliberate design—the LTA keeping the distance travelled on new bus routes at an optimal level?

It’s also clear that long bus routes provide excellent redundancy to Singapore’s transport system—always a good thing, if the engineering podcast I listen to is anything to go by. Then-Minister for Transport Ong Ye Kung has admitted as much in Parliament when he said that long routes remain a solid backbone to our transport network, even when most of them run at a loss. Most of our routes, in fact, are trunk routes, despite the speed and geographical extent of our rail lines. Shorter routes aren’t necessarily more cost-effective due to the limiting factors of fleet maintenance and drivers’ wages (as much as Minister Ang Wei Neng would like to think otherwise). And even if shorter services are more reliable, one can’t deny the added perceived annoyance and trip variability that multiple, brief transfers can add to an otherwise-seamless journey. If you’re searching for an station entrance, crossing to a bus stop, or waiting for a couple of bunched-up feeders in a strange neighbourhood, all that wait time is going to add up.

What the numbers can’t tell us, however, are the associated impressions of mobility that have run deep over the years along these long bus lines. I can’t tell you how many times the 162 has saved my life running past midnight along Plaza Singapura on a Friday night, or the weekly relief at taking the 52 back down Marymount Road from Maju Camp. It can’t tell you how I know the shape of the 410 both ways from the drumming of my skull against the hideous beige walls. And the data is silent on that one elderly man in Tanglin Halt, who can no longer take the bus from his doorstep to visit his old friends all along the southwest coast, from Clementi to Redhill and beyond…

All this, too, is part of the data. The stories and the numbers don’t lie. In our hearts and on our roads, the long bus ride is here to stay. :)