Now that we’ve looked at D1 and D2, let’s look at another ISB service that was formerly one route but later split into two: Service B.

When I checked the university website archives for old routings, the furthest back I was able to reach was end-2002. At that time, we had three services: A, B and C, where A was already numbered as A1 and A2.

A was a pair of services that circled the entire campus. B operated as one loop service which linked Engineering with Law and Business. C operated as a loop linking Engineering with Science.

Route B is coloured green on system maps and on route boards. Until the split into B1 and B2, the route of B was largely unchanged. Yet the same cannot be said for the role it fulfilled, thanks to many faculty movements affecting the identities of the stops. For years, B may not have changed in what it looked like, but what changed was what it did.

First Generation Map

The very first incarnation of B operated out of Kent Vale Bus Terminal, which was a small terminal used only by ISBs. It was located on the site of the current Kent Vale housing complex.

The buses would enter the Faculty of Engineering at E3A, then go back out to the main road past OED (now Museum) and then travel through Central Forum to eventually loop at Carpark 13. Back then, this stop served the Law and Business faculties. After that, it would cross over to Carpark 15 to serve Temasek and Eusoff halls before going back the way it came.

This is the first-generation GIF map of service B, showing its shape.

Second Generation Map

In AY06/07, new maps were published to coincide with the “promotion” of the supplementary service to Service D. These featured the exact same routing as before, just on a better looking backdrop.

Behind the scenes, though, changes were afoot. Over this period, B slowly shifted from connecting Engineering and Law/Business to connecting Engineering and Computing.

The Carpark 13 bus stop, which served as a looping point for B, is located next to two buildings. The newer one, further from the stop, was originally Law School while the building directly adjacent to the stop was BIZ1.

In 2007, Law vacated the building and SoC shifted over naming it COM1, while in 2010 SoC took over BIZ1 and renamed it COM2.

This is reflected in the stop listing for B, which in 2007 listed the looping point as Carpark 13 @ BIZ instead of BIZ/Law.

After SoC fully moved to its present location, the stop was renamed as COM2, and service B no longer served Law students who were instead served by a dedicated BTC shuttle. Business students continued to take the B from COM2, as it was fairly near BIZ2.

Third Generation Map

Around the time UTown was opened to ISBs in 2011, NUS redesigned their maps again.

I know, I know. The map looks the same. But if you look closely, the campus map behind has been updated to reflect the new locations of the faculties. This map clearly shows B as an Engin-SoC route.

There is also a small change you might have missed. By the time this third generation map was used (around 2011), the starting point of B had changed.

Previously, B started trips at Kent Vale Terminal. Some of our older bus uncles still remember those days. However, around the time UTown opened, the entire Kent Vale carpark was closed for redevelopment into an apartment complex for international faculty.

I do not have the exact date of closure, but online digging shows a mention of the carpark closing on 28th February 2010 so I shall assume that it occurred no earlier than that date. In any case, by July 2010, route B was starting its trips from Kent Ridge Bus Terminal (where SBS routes 33 and 95 also started) instead.

Two bus stops were added to the route in lieu: Block EA and The Japanese Primary School (across Clementi Rd from Blk EA). This improved connectivity for Engineering students, but resulted in difficulty for the drivers as they had to make a right turn into NUS immediately after stopping at the Japanese school by filtering across three lanes of traffic.

Kent Vale apartment complex opened fully in 2012; the closest stop was the Japanese Primary School. B connected faculty members living in Kent Vale to the southern half of the campus, while C connected Kent Vale to the northern half.

Bus Stop Removals (2015)

From 2015 onwards, more significant changes were made to the B route because the fleet was changed to larger buses.

Firstly, the stop inside Engineering at E3A was removed in January. Commuters were directed to use the EA-Japanese School pair of bus stops instead.

Then, in August, the bus stops outside Temasek Hall and Eusoff Hall were decommissioned, so service B would make a right turn after departing COM2 and use the main road to Ventus, not entering Carpark 15.

On the other hand, boarding and alighting were allowed at Kent Ridge Bus Terminal which is within walking distance from Eusoff Hall. This was at the request of NUSSU as a mitigatory measure for the loss of bus stops.

Fourth Generation Map (2015)

After a series of amendments and a new website in 2015, OCA redesigned the maps. The fourth-generation map, showing the route without the three stops, is shown below.

On 27 June 2016, in light of the safety concerns and difficulty faced by the ISB drivers in turning right after the Japanese School, NUS decided to remove the Japanese Primary School bus stop from the B route. The role of connecting Kent Vale to the southern half of NUS KRC was taken over by Service BTC1.

That was the last change I know of to service B prior to its split.

UT-CLB/UT-CCE Direct (2013-2017)

After UTown opened, it was found that there was significant crowding from UTown to Central Forum and vice versa. In August 2013, alongside the split of D1 and D2, the UT-CLB Direct bus was introduced. I believe it drew from the B bus and driver pool, but not necessarily so.

The original UT-CLB service would travel between UTown, Central Library and Computer Centre. The driver would start his trip at Computer Centre (now IT), complete a few rounds and then end the route at Central Library where no students would board.This turnaround was accomplished by U-turning the bus outside the Central Library. Back then, the CLB stop was a fair bit up the hill so buses could use the U-turn slot that was carved into the very wide road.


However, in July 2016, the CLB bus stop was slated to be shifted down the hill. This shift caused it to be after the U-turn slot (see poster above; click to enlarge), and originally, the UT-CLB Direct was modified to stop at CCE instead.

However, from March 2016, the route of UT-CLB was changed to an anticlockwise loop. This change was not reflected accurately in the poster above. The circle would go from UTown to EA to Computer Centre and back to UTown again, as below.


On 1 August 2016, the route was changed to skip EA and just travel between UTown and CCE, so it was no longer an anticlockwise circle. It drove past YIH and U-turned near CLB, as it used to. It was renamed UT-CCE Direct, and a fourth-generation map was prepared for it.

However, this only lasted for one semester, as you will see below.

Split into B1 and B2 (2017)

In January 2017, B was merged with the UT-CCE direct and split into two different routes: B1 and B2. This had the effect of changing the service B role once again, from an Engin-SoC link to a UTown-Biz and UTown-Engin link. This came following suggestions by my NUSSU pre-predecessor Hao Jing (now VP of the 40th EXCO).

It also made the service one of the most confusing for students. On the surface, B1 starts at Kent Ridge Bus Terminal and ends at Carpark 11. B2 starts at Carpark 11 and ends at Kent Ridge Terminal.

Thus, the two services operate in pairs: each will usually alternate between the two, and many drivers basically see B1/B2 as a single trip there and back again. The exception is during nights and Saturdays where only B2 runs from CP11 to KRBT and then heads back to CP11 off service to repeat.

Basically, the B services now skip COM2/Carpark 13 (their original loop point which remained unchanged for years) and now use BIZ/CP11 as their turnaround cum layover.

The maps for the new services B1 and B2 remained in a single PDF file, titled “Service B”. This was most likely done by OCA to ensure that websites linking to the PDF via URL would continue to work. However, B1 and B2 were split into two pages.

In part, the confusing nature of B1/B2 was one reason why I, as the NUSSU representative, called on OCA to reinstate the bus route maps which had gone missing from the website, since the services are not directional inverses of one another. They also come so infrequently that by the time you see one you could have ostensibly forgotten the last time you rode it!

B2 most clearly illustrates the merger of B and UT-CLB (the anticlockwise loop version). It leaves Business, heads to IT and then dips into UTown before heading out to Clementi Rd (EA) and then Kent Ridge Bus Terminal. The traces of both routes are clearly visible.

B1, however, is not the reverse direction of B2. Since the Japanese School bus stop was already skipped, and BTC1 connected passengers from Kent Vale to the southern half of the campus, few commuters were accustomed to using it.

Instead, since B1 had to make its way from KRBT to UTown, OCA decided to route B1 via IT as well. Thus, the demand from IT to UTown is covered by both B1 and B2 in addition to D1. While less frequent, B1 and B2 actually give a shorter ride as they do not stop at Museum before entering UTown.

So in terms of their purpose, B1 now served as a supplement to D1 (how things have changed!) between UTown, CLB and Business, while B2 continued to serve Business and Engineering. Both routes bypass COM2, making them useful for students at Business or Kent Ridge/Sheares halls.


Since the split to B1 and B2 occurred long after buses without electronic signs were phased out completely from the network, when a bus does need to use the B board due to signage malfunction, a number had to be taped onto it.

The end point on the board is not an issue since the two ends listed still make sense! For B1, it was conveniently printed as Business School — but it actually refers to CP13! It’s a leftover from when the area was still Law/Biz. For B2, the listed stop “Opposite Block EA” refers to the EA stop, now standing in for B2 which ends at Kent Ridge Terminal.

There is another B board that has “Computing” listed as the destination (the header image for this article), which was not commonly used after the split as it would be misleading.

Fifth Generation Map (2018)

The fifth-generation maps now show the bus stops over the fourth-generation map.

COVID-19 Suspension (2020)

Due to the COVID-19 pandemic, students had to be segregated into zones to minimise the chance of cross-infection across different faculties due to NUS’ connected nature. As such, ISB routes were revised and replaced from 20 July 2020 to facilitate zoning, and all existing services were suspended for AY20/21 Semester 1. The service names were not reused.

B1 and B2, however, had already been suspended from 13 April 2020 due to the circuit breaker measures and the corresponding changes to the ISB network.

Reinstatement (2020)

On 6 December 2020, following the lifting of the zoning policy, the original pre-zoning routes were reinstated. OCA uploaded route information in image form on their website.

Withdrawal (2021)

As part of the New ISB Network, Services B1 and B2 were withdrawn from 19 July 2021 onwards. As Service B1 did not operate during vacation periods, it had already not been in operation for some time. The role of these services was replaced by Service E, which inherited its green colour and was to be introduced from 2 August 2021 as it was also a term-time service.

With that, Service B’s history came to an end in 2021. Thus concludes the article on the B services, now B1 and B2: a bus whose purpose changed wildly in comparison to its relatively tamer route amendments. The next installment will cover C, whose purpose but not routing remained constant through the years.

Further Reading:

All Episodes

16 thoughts on “History of Bus Routes Ep 2: B1/B2

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