History of Services 91 - 100

Service 91 (1971 - 1989)

Operator	Year	Date	Service changes
STC	1971	11 April	Introduced between Paya Lebar Airport Ter and Prince Edward Ter under 1971 Bus Reorganisation.
UBC		6 December	Operations transferred to UBC.
	1974	3 February	Amended to ply Paya Lebar Rd, Tg Katong Rd, Dunman Rd, Old Airport Rd and Mountbatten Rd under 1974 Bus Rationalisation, skipping MacPherson Rd and Aljunied Rd.
		8 December	Amended to ply the extended Robinson Rd, skipping Market St.
	1976	15 February	Serves new staggered bus stop between Bank of India and Hong Leong Holdings along Robinson Rd.
		14 March	Serves new staggered bus stop outside The Cenotaph along Connaught Dr, skipping the bus stop opposite Singapore Cricket Club.
		1 October	Amended to Jln Ang Teng Ter.
		30 December	Amended to ply Sims Ave/Geylang Rd and the extended Tg Katong Rd, skipping Guillemard Rd.
	1978	15 January	Amended to ply Jln Sultan, skipping Sumbawa Rd.
	1979	11 February	Amended to ply the extended Shenton Way, Palmer Rd and Anson Rd, skipping Parsi Rd.
	1981	30 June	Amended to loop at Airport Rd with the closure of Jln Ang Teng Ter.
		5 July	Shortened to Geylang Fringe Car Pk.
	1989	5 November	Discontinued.

Service 91 (since 1995)

Operator	Year	Date	Service changes
	1995	13 February	Introduced between Buona Vista Ter and Ayer Rajah Cres (Loop), operating on weekdays and Saturdays only.
	1997	TBC	First bus revised to 0630 hrs. Last bus extended to 2000 hrs.
	1999	17 July	Last bus brought forward to 1800 hrs on Saturdays.
(Current)	2006	TBC	Serves merged bus stop opposite Buona Vista Stn along Nth Buona Vista Rd with the closure of the staggered bus stop.
	2012	9 April	Skips abolished bus stop outside Basement Food Court along Ayer Rajah Cres.
	2014	3 December	Designated wheelchair-accessible bus service (WAB).

Short Trip 91A (2001 - 2012)

Operator	Year	Date	Service changes
	2001	TBC	Introduced from Buona Vista Ter to Ayer Rajah Cres (Ayer Rajah Bus Pk) during morning peak hours on weekdays.
	2006	TBC	Serves merged bus stop opposite Buona Vista Stn along Nth Buona Vista Rd with the closure of the staggered bus stop.
	2012	TBC	Discontinued.

Service 92 (1971 - 1993)

Operator	Year	Date	Service changes
UBC	1971	11 April	Introduced between Paya Lebar Airport Ter and Gagak Selari Barat Ter under 1971 Bus Reorganisation.
	1972	18 June	Amended to ply Bendemeer Rd towards Gagak Selari Barat Ter with the conversion of Serangoon Rd to one-way traffic.
	1973	11 March	Amended to ply Hoot Kiam Rd towards Jln Ang Teng Ter with the conversion of Irwell Bank Rd to one-way road.
	1974	3 February	Extended to Alexandra Rd (Alexandra Hosp) Ter under 1974 Bus Rationalisation.
		24 February	Amended to ply Grange Rd and Orchard Blvd towards Alexandra Rd (Alexandra Hosp) Ter with the conversion of Orchard Rd to one-way road.
		1 October	Serves new bus stop outside Nan Hwa Girls' High Sch along Bencoolen St.
			Serves merged bus stop outside Sri Srinivasa Perumal Tp along Serangoon Rd.
	1976	1 October	Amended to Jln Ang Teng Ter.
	1981	30 June	Amended to loop at Airport Rd with the closure of Jln Ang Teng Ter.
	1985	28 April	Integrated with Service 185 and extended to Clementi Int.
	1988	11 January	Serves merged bus stop along Ayer Rajah Rd.
		8 March	Amended to ply Clementi Ave 3 with the abolition of right turning from Clementi Ave 3 to Commonwealth Ave West.
	1992	19 July	Amended to ply Orchard Lk due to the closure of Grange Rd to facilitate road expansion works.
	1993	23 May	Integrated with Service 14 and discontinued under TransitLink Network Integration Exercise Phase 13.

Service 92 (since 1997)

Operator	Year	Date	Service changes
	1997	6 October	Re-numbered from Service M1 as a service between Science Pk Dr (Blk 85) and Mt Sinai Dr (Loop).
	1999	TBC	Last bus extended to 2100 hrs on weekdays.
(Current)	2005	15 January	Serves new bus stop between Hse Nos. 33 and 35 along Mt Sinai Dr.
	2007	26 November	Amended to start from Ghim Moh Ter and loop at Science Pk Dr/Mt Sinai Dr.
	2014	28 September	Serves 3 new bus stops outside Blk 85 and outside and opposite The Rutherford along Science Pk Dr.
		29 September	Designated wheelchair-accessible bus service (WAB).
	2016	19 December	Last bus extended to 2035 hrs on weekdays and 2036 hrs on Saturdays.
	2023	10 September	Serves new bus stop opposite Ghim Moh Ter along Ghim Moh Rd.

Short Trip 92A (2001 - 2023)

Operator	Year	Date	Service changes
	2001	TBC	Introduced from Science Pk Dr (Blk 85) to Ghim Moh Rd (Blk 13) during evening peak hours on weekdays.
	2012	TBC	Extended to start from Ghim Moh Ter.
	2014	29 September	Designated wheelchair-accessible bus service (WAB).
	2023	27 November	Discontinued.

Short Trip 92B (2007 - 2023)

Operator	Year	Date	Service changes
	2007	26 November	Introduced from Ghim Moh Ter to Science Pk Dr (Blk 85) during peak hours and after the last bus of Service 92 on weekdays and Saturdays.
	2014	28 September	Serves 3 new bus stops outside Blk 85 and outside and opposite The Rutherford along Science Pk Dr.
		29 September	Designated wheelchair-accessible bus service (WAB).
	2016	19 December	Last bus extended to 2120 hrs on weekdays and 2123 hrs on Saturdays.
	2017	26 December	Shortened to terminate at Science Pk Dr (The Rutherford).
	2023	27 November	Discontinued.

Service 92M

Operator	Year	Date	Service changes
(Current)	2015	30 August	Introduced between Ghim Moh Ter and Nth Buona Vista Rd (Loop), operating on Sundays and Public Holidays only. Wheelchair-accessible at launch.
	2017	9 July	Last bus extended to 2005 hrs, with special departures operating between Ghim Moh Ter and Nth Buona Vista Rd (Buona Vista Stn Exit D) until 2043 hrs.
	2023	10 September	Serves new bus stop opposite Ghim Moh Ter along Ghim Moh Rd.

Service 93

Operator	Year	Date	Service changes
UBC	1971	11 April	Introduced between Paya Lebar Airport Ter and Alexandra Rd Ter under 1971 Bus Reorganisation.
	1976	1 October	Amended to Jln Ang Teng Ter.
	1981	30 June	Amended to loop at Airport Rd with the closure of Jln Ang Teng Ter.
	1985	13 January	Extended to World Trade Ctr Ter.
	1987	12 August	Skips abolished bus stop after Joan Rd along Lornie Rd.
	1993	23 May	Extended to Eunos Int under TransitLink Network Integration Exercise Phase 13.
	1999	TBC	Skips abolished pair of bus stops outside and opposite Wishart Rd along Telok Blangah Rd.
(Current)	2004	TBC	Skips abolished bus stop outside Nanyang Pr Sch along Farrer Rd.
		TBC	First bus from HarbourFront Int brought forward to 0520 hrs on weekdays and Saturdays.
	2007	TBC	Skips abolished bus stop before Paya Lebar Rd along Airport Rd to facilitate the construction of KPE.
		TBC	First bus from HarbourFront Int brought forward to 0515 hrs on weekdays.
	2009	8 March	Skips a pair of bus stops outside and opposite Bartley Sec Sch with the realignment of the junction of Upp Paya Lebar Rd and Bartley Rd.
	2012	3 December	Designated wheelchair-accessible bus service (WAB).
	2018	28 October	Amended to ply southbound Lornie Highway towards HarbourFront Int.
	2019	23 June	Amended to ply northbound Lornie Highway towards Eunos Int.

Service 93A (1971 - 1974)

Operator	Year	Date	Service changes
UBC	1971	25 April	Introduced between Jln Ang Teng Ter and Jln Bt Merah Ter.
	1974	3 February	Discontinued under 1974 Bus Rationalisation.

Service 94 (1971 - 1989)

Operator	Year	Date	Service changes
STC	1971	11 April	Introduced between Jln Kolam Ayer Ter and Ulu Pandan Ter under 1971 Bus Reorganisation.
		9 May	Amended to ply Tiong Bahru Rd and Tanglin Rd.
ABS		6 December	Operations transferred to ABS.
	1972	18 June	Amended to ply Bendemeer Rd towards Ulu Pandan Ter with the conversion of Serangoon Rd to one-way traffic.
	1974	8 December	Amended to ply the extended Robinson Rd, skipping Market St.
	1975	2 February	Amended to ply new slip road from Tiong Bahru Rd to Outram Rd with the conversion of Seng Poh Rd to one-way traffic.
	1976	15 February	Serves staggered bus stop between Bank of India and Hong Leong Holdings along Robinson Rd.
		TBC	Amended to ply Kallang Bahru, skipping Serangoon Rd/Bendemeer Rd.
		13 December	Extended to Sims Pl Ter.
	1977	17 October	Shortened to loop at Shenton Way.
	1979	11 February	Amended to ply the extended Shenton Way, Keppel Rd and Anson Rd, skipping Parsi Rd.
	1981	11 October	Serves new staggered bus stop outside Tunas Bldg along Anson Rd, skipping the bus stop outside Intl Plaza.
	1982	22 May	Amended to ply Aljunied Rd, MacPherson Rd, Bendemeer Rd and Geylang Bahru, skipping Jln Kolam Ayer.
	1988	3 January	Serves new staggered bus stop opposite Treasury Bldg along Shenton Way, skipping the bus stop opposite Marina Hse.
	1989	11 June	Discontinued.

Service 94 (since 1989)

Operator	Year	Date	Service changes
	1989	5 November	Introduced between Eunos Ter and Airport Rd (Loop).
		10 December	Amended to Eunos Int.
	1993	23 May	Converted to a day service on weekdays and Saturdays under TransitLink Network Integration Exercise Phase 13.
(Current)	2008	TBC	Serves new bus stop after Defu Lane 12 along Airport Rd.
		24 September	Skips abolished bus stop outside KB Warehouse Cplx along Airport Rd.
	2010	28 June	Designated wheelchair-accessible bus service (WAB).

Short Trip 94A

Operator	Year	Date	Service changes
	2000	TBC	Introduced from Eunos Int to Airport Rd (RSAF Paya Lebar) during morning peak hours on weekdays and Saturdays.
(Current)	2008	TBC	Serves new bus stop after Defu Lane 12 along Airport Rd.
	2010	28 June	Designated wheelchair-accessible bus service (WAB).

Service 95 (1971 - 1988)

Operator	Year	Date	Service changes
UBC	1971	22 April	Introduced between Paya Lebar Airport Ter and Havelock Rd (Loop).
	1972	11 June	Amended to ply the extended Upp Cross St with the partial conversion of Havelock Rd to one-way traffic, skipping New Bridge Rd.
	1973	11 March	Amended to ply Hoot Kiam Rd towards Jln Ang Teng Ter with the conversion of Irwell Bank Rd to one-way traffic.
	1974	3 February	Amended to Lor 4 Toa Payoh, Toa Payoh Ctrl and Lor 2 Toa Payoh and extended to Ulu Pandan Ter under 1974 Bus Rationalisation.
	1976	1 October	Amended to Jln Ang Teng Ter.
	1977	19 June	Amended to ply Paterson Rd, Orchard Blvd and Grange Rd towards Ulu Pandan Ter with the full conversion of Orchard Rd to one-way traffic.
	1980	20 January	Amended to ply Thomson Flyover towards Ulu Pandan Ter, skipping Thomson Rd and a portion of Whitley Rd.
	1981	15 June	Extended to Clementi Int.
		30 June	Amended to loop at Airport Rd with the closure of Jln Ang Teng Ter.
	1986	16 November	Serves new staggered bus stop outside Thong Teck Bldg along Scotts Rd, skipping the bus stop outside Metro Orchard.
	1988	8 March	Amended to ply Clementi Ave 3 with the abolition of right turning from Clementi Ave 3 to Commonwealth Ave West.
		13 March	Discontinued with the introduction of Service 105.

Service 95 (since 1990)

Operator	Year	Date	Service changes
	1990	15 January	Introduced between Buona Vista Ter and Lower Kent Ridge Rd (Loop), operating on weekdays and Saturdays only.
	1993	23 May	Amended to ply Holland Dr, Holland Ave and Commonwealth Ave towards Lower Kent Ridge Rd.
	1996	TBC	Extended to operate on Sundays and Public Holidays.
	2001	23 July	Extended to loop at Kent Ridge Ter.
(Current)	2006	17 December	Amended to start from Kent Ridge Ter and loop at Holland Dr.
	2010	18 October	Designated wheelchair-accessible bus service (WAB).
	2011	29 May	Serves new pair of bus stops outside Kent Ridge Stn along Lower Kent Ridge Rd.
	2013	13 October	Serves relocated bus stop opposite Blk 21 along Holland Dr with the abolition of the bus stop outside Blk 17 along Nth Buona Vista Rd.

Short Trip 95A (2001 - 2011)

Operator	Year	Date	Service changes
	2001	TBC	Introduced from Buona Vista Ter to Lower Kent Ridge Rd (NUH) during morning peak hours on weekdays.
	2006	17 December	Shortened to start from Nth Buona Vista Rd (Opp Buona Vista Stn) with the route amendment of Service 95.
	2010	18 October	Designated wheelchair-accessible bus service (WAB).
	2011	29 May	Serves new bus stop outside Kent Ridge Stn along Lower Kent Ridge Rd.
		TBC	Discontinued.

Short Trip 95B

Operator	Year	Date	Service changes
(Current)	2004	TBC	Introduced from Kent Ridge Ter to Nth Buona Vista Rd (Buona Vista Stn) during evening peak hours on weekdays.
	2010	18 October	Designated wheelchair-accessible bus service (WAB).
	2011	29 May	Serves new bus stop outside Kent Ridge Stn along Lower Kent Ridge Rd.

Short Trip 95C (2005 - 2010)

Operator	Year	Date	Service changes
	2005	26 September	Introduced from Buona Vista Ter to Lower Kent Ridge Rd (Kent Ridge Hall) during morning peak hours on weekdays.
	2006	17 December	Shortened to start from Nth Buona Vista Rd (Opp Buona Vista Stn) with the route amendment of Service 95.
	2010	TBC	Discontinued.

Short Trip 95D (2006 - 2010)

Operator	Year	Date	Service changes
	2006	17 December	Introduced from Kent Ridge Ter to Holland Rd (Holland Village) during peak hours on weekdays and after the last bus of Service 95 daily.
	2010	TBC	Discontinued.

Service 96

Operator	Year	Date	Service changes
	1982	16 August	Introduced between Clementi Int and Kent Ridge Cres (Loop), operating on weekdays and Saturdays only.
	1986	1 June	Skips abolished bus stop before Ayer Rajah Rd along Clementi Rd.
	1988	8 March	Amended to ply Clementi Ave 3 with the abolition of right turning from Clementi Ave 3 to Commonwealth Ave West.
	1990	2 July	Extended to operate on Sundays and Public Holidays.
	1996	TBC	First bus brought forward to 0700 hrs on Sundays and Public Holidays.
	1999	TBC	Last bus extended to 2300 hrs on Sundays and Public Holidays.
	2002	TBC	First bus brought forward to 0645 hrs on weekdays.
	2006	29 October	Amended to Clementi Temp Int.
	2011	26 November	Amended to Clementi Integrated Transport Hub.
	2012	25 June	Designated wheelchair-accessible bus service (WAB).
(Current)	2016	26 June	Operations transferred to Tower Transit Singapore.

Short Trip 96A

Operator	Year	Date	Service changes
	2000	TBC	Introduced from Clementi Int to Kent Ridge Cres (NUS Raffles Hall) during morning peak hours on weekdays.
	2006	29 October	Amended to Clementi Temp Int.
	2011	26 November	Amended to Clementi Integrated Transport Hub.
	2012	25 June	Designated wheelchair-accessible bus service (WAB).
(Current)	2016	26 June	Operations transferred to Tower Transit Singapore.

Short Trip 96B

Operator	Year	Date	Service changes
	2007	TBC	Introduced from Clementi Temp Int to Commonwealth Ave West (Clementi Stn) during evening peak hours on weekdays.
	2011	26 November	Amended to Clementi Integrated Transport Hub.
	2012	25 June	Designated wheelchair-accessible bus service (WAB).
(Current)	2016	26 June	Operations transferred to Tower Transit Singapore.
	2021	2 August	Shortened to start from Kent Ridge Cres (NUS Fac of Design & Env).

Service 97

Operator	Year	Date	Service changes
	1983	29 August	Introduced between Jurong East Ter and Connaught Dr (Loop) as a peak hour service on weekdays and Saturdays.
		18 December	Integrated with Service 86, extended to Hougang Int and converted to full day service.
	1985	30 June	Amended to Jurong East Int.
	1988	3 January	Serves new staggered bus stop opposite Treasury Bldg along Shenton Way, skipping the bus stop opposite Marina Hse.
		6 June	First bus from Hougang Int brought forward to 0545 hrs on Sundays and Public Holidays.
		18 December	Integrated with Service 79 and amended to ply AYE and Alexandra Rd, skipping Clementi Rd and Pasir Panjang Rd.
	1994	17 December	Extended to Hougang Ctrl Int.
	1998	24 May	Amended to Hougang Ctrl Temp Int.
	1999	TBC	Skips abolished pair of bus stops outside and opposite Wishart Rd along Telok Blangah Rd.
		TBC	Last bus from Jurong East Int extended to 2345 hrs daily.
	2001	20 May	Amended back to Hougang Ctrl Int.
	2002	TBC	Serves new pair of bus stops after Sommerville Rd and after Sunshine Lodge along Upp Serangoon Rd.
	2003	20 June	Serves new pair of bus stops outside Potong Pasir Stn along Upp Serangoon Rd.
		27 July	Shortened to loop at Temasek Ave from Jurong East Int under North East MRT Line Rationalisation Phase 2.
	2005	12 June	Serves new bus stop outside Science Pk along AYE.
	2006	29 October	Serves new bus stop outside VivoCity along Telok Blangah Rd.
	2008	7 December	Skips abolished bus stop opposite Temenggong D Mque along Telok Blangah Rd.
	2010	26 April	Amended to Marina Ctr Ter, skipping Collyer Quay/Fullerton Rd and Esplanade Dr.
	2011	17 December	Amended to Jurong East Temp Int.
	2012	25 June	Designated wheelchair-accessible bus service (WAB).
	2013	1 December	Serves new bus stop outside Downtown Stn along Central Blvd.
(Current)	2016	12 June	Operations transferred to Tower Transit Singapore.
	2020	6 December	Amended to relocated Jurong East Temp Int and amended to ply Jurong East St 12, skipping Jurong Gateway Rd, Jurong East Ctrl and Jurong Town Hall Rd.
	2021	27 February	Amended to the relocated Marina Ctr Ter.
	2024	28 January	Serves relocated bus stop after Clementi Swim Cplx along AYE.

Short Trip 97A (2000 - 2010)

Operator	Year	Date	Service changes
	2000	TBC	Introduced from Jurong East Int to Fullerton Rd (Fullerton Sq) during morning peak hours on weekdays.
	2003	27 July	Extended to terminate at Raffles Ave (Opp Marina Sq), operating after the last bus of Service 97 daily.
	2010	26 April	Discontinued.

Short Trip 97B (2006 - 2010)

Operator	Year	Date	Service changes
	2006	11 September	Introduced from Jurong East Int to Telok Blangah Rd (HarbourFront Stn) during morning peak hours on weekdays.
	2010	26 April	Discontinued.

Service 98

Operator	Year	Date	Service changes
	1984	1 January	Introduced between Jurong Int and Jurong East Ctrl (Loop).
	1985	30 June	Amended to start from Jurong East Int and loop at Jurong Int.
	1990	1 July	Amended to loop at Jln Ahmad Ibrahim from Jurong East Int.
	1991	20 January	Integrated with Service 247, amended to ply Jurong West St 51 and Boon Lay Way and extended to loop at Jurong Pier Rd under TransitLink Network Integration Exercise Phase 2.
	1995	15 January	Alternate trips introduced during off peak hours daily, looping at Corporation Rd.
	1999	TBC	Alternate trips during off peak hours re-numbered Short Trip 98A.
	2003	TBC	Amended to loop at Jurong Pier Way.
	2004	TBC	Skips abolished pair of bus stops outside Jurong Power Stn and outside JPL Ind Pte Ltd along Jurong Pier Rd.
	2011	17 December	Amended to Jurong East Temp Int.
	2012	25 June	Designated wheelchair-accessible bus service (WAB).
(Current)	2016	26 June	Operations transferred to Tower Transit Singapore.
	2020	6 December	Amended to relocated Jurong East Temp Int and serve new bus stop before Jurong East Stn along Jurong Gateway Rd.

Short Trip 98A (1999 - 2008)

Operator	Year	Date	Service changes
	1999	TBC	Re-numbered from alternate trips of Service 98 as a short-trip service between Jurong East Int and Corporation Rd (Loop), operating during off peak hours daily.
	2008	28 January	Re-numbered Service 98M.

Short Trip 98A (since 2011)

Operator	Year	Date	Service changes
	2011	3 May	Introduced from Boon Lay Way (Lakeside Stn) to Corporation Rd (Corporation Pl) during evening peak hours on weekdays.
	2012	25 June	Designated wheelchair-accessible bus service (WAB).
(Current)	2016	26 June	Operations transferred to Tower Transit Singapore.

Short Trip 98B

Operator	Year	Date	Service changes
	2012	16 April	Introduced from Boon Lay Way (Lakeside Stn) to Jurong Pier Way (Jurong Island Checkpt) during morning peak hours on weekdays.
		25 June	Designated wheelchair-accessible bus service (WAB).
	2013	2 January	Extended to start from Jurong West Ave 1 (Blk 490).
(Current)	2016	26 June	Operations transferred to Tower Transit Singapore.

Service 98M

Operator	Year	Date	Service changes
	2008	28 January	Converted from Short Trip 98A as a service between Jurong East Int and Jln Ahmad Ibrahim (Loop) as an alternate route of Service 98 during off peak hours daily.
	2011	17 December	Amended to Jurong East Temp Int.
	2012	25 June	Designated wheelchair-accessible bus service (WAB).
(Current)	2016	26 June	Operations transferred to Tower Transit Singapore.
	2020	6 December	Amended to relocated Jurong East Temp Int and serve new bus stop before Jurong East Stn along Jurong Gateway Rd.

Service 99

Operator	Year	Date	Service changes
	1985	16 June	Introduced between Jurong East Ter and Boon Lay Dr (Loop).
		30 June	Amended to Jurong East Int.
	1988	13 March	Extended to start from Clementi Int and extended to loop at Jurong West St 91.
		24 April	Serves new pair of bus stops before and after Upp Jurong Rd along Pioneer Rd Nth.
	1989	TBC	Amended to ply Boon Lay Ave (towards Jurong West St 91), skipping Boon Lay Dr, Boon Lay Way and Jln Boon Lay.
	1991	19 May	Amended to ply Jurong West Ave 5 and Jurong West St 72, skipping Pioneer Rd Nth.
(Current)	2003	TBC	Serves additional bus stop outside Blk 673C along Jurong West Ave 4.
	2006	29 October	Amended to Clementi Temp Int.
	2007	15 July	Serves new bus stop outside Blk 207 along Boon Lay Pl.
	2011	27 June	Designated wheelchair-accessible bus service (WAB).
		26 November	Amended to Clementi Integrated Transport Hub.
	2015	21 November	Extended to Joo Koon Integrated Transport Hub, skipping Jurong West St 92.

Service 100 (April - May 1971)

Operator	Year	Date	Service changes
STC	1971	11 April	Introduced between Serangoon Gdn Ter and Prince Edward Ter under 1971 Bus Reorganisation.
		9 May	Integrated with Service 100A and re-numbered Service 100/100A.

Service 100 (since 1974)

Operator	Year	Date	Service changes
	1974	3 February	Re-numbered from Service 100/100A as a service between Serangoon Gdn Ter and Prince Edward Ter under 1974 Bus Rationalisation.
		8 December	Amended to ply the extended Robinson Rd, skipping Market St.
	1975	2 March	Amended to ply Sims Ave towards Serangoon Gdn Ter with the conversion of Geylang Rd to one-way traffic.
		21 July	Amended to ply St. Andrew's Rd and Stamford Rd, skipping Coleman St and Hill St.
	1976	15 February	Serves new staggered bus stop between Bank of India and Hong Leong Holdings along Robinson Rd.
		14 March	Serves new staggered bus stop outside The Cenotaph along Connaught Dr, skipping the bus stop opposite Singapore Cricket Club.
		16 August	Amended to ply Aljunied Rd with the introduction of Service 60, skipping MacPherson Est in both directions.
	1977	31 October	Amended to skip Serangoon Gdn Est with the introduction of Service 217.
	1979	11 February	Amended to ply the extended Shenton Way, Palmer Rd and Anson Rd, skipping Parsi Rd.
	1985	13 January	Extended to World Trade Ctr Ter.
	1988	3 January	Serves new staggered bus stop opposite Treasury Bldg along Shenton Way, skipping the bus stop opposite Marina Hse.
		13 March	Amended to Serangoon Int.
	1989	5 November	Integrated with Service 20, extended to Ghim Moh Ter and amended to ply Beach Rd, skipping Nth Bridge Rd/Victoria St.
	1994	3 July	Amended to ply Crawford St towards Serangoon Int.
	1996	TBC	Serves additional bus stop outside Kallang Stn along Sims Ave.
	1999	TBC	Skips abolished pair of bus stops outside and opposite Wishart Rd along Telok Blangah Rd.
(Current)	2002	TBC	Serves new pair of bus stops after Sommerville Rd and after Sunshine Lodge along Upp Serangoon Rd.
	2006	29 October	Serves new bus stop outside VivoCity along Telok Blangah Rd.
	2007	28 April	Serves additional bus stop outside Victoria Concert Hall along Fullerton Rd.
	2008	7 December	Skips abolished bus stop opposite Temenggong D Mque along Telok Blangah Rd.
	2011	3 September	Amended to Serangoon Integrated Transport Hub.
		26 September	Designated wheelchair-accessible bus service (WAB).
	2016	1 May	Amended to ply Esplanade Dr with the partial closure of Fullerton Rd.
	2017	12 March	Amended to ply Upp Serangoon Rd and the diverted Upp Aljunied Rd.
	2021	26 December	Amended to ply Esplanade Dr towards Ghim Moh Ter with the closure of Connaught Dr.
	2023	10 September	Extended to terminate at Ghim Moh Rd (Blk 7) towards Ghim Moh Ter.

Service 100/100A (1971 - 1974)

Operator	Year	Date	Service changes
STC	1971	9 May	Re-numbered from Service 100 as a service between Serangoon Gdn Ter and Prince Edward Ter.
ABS		6 December	Operations transferred to Associated Bus Service (ABS).
	1974	3 February	Re-numbered Service 100 under 1974 Bus Rationalisation.

Service 100A (April - May 1971)

Operator	Year	Date	Service changes
STC	1971	11 April	Introduced between Serangoon Gdn Ter and Finlayson Green (Loop) under 1971 Bus Reorganisation.
		9 May	Integrated with Service 100 and discontinued.

Short Trip 100A (since 2000)

Operator	Year	Date	Service changes
	2000	TBC	Introduced from Serangoon Int to Aljunied Rd (Aljunied Stn) during morning peak hours on weekdays.
(Current)	2002	TBC	Serves new bus stop after Sunshine Lodge along Upp Serangoon Rd.
	2011	3 September	Amended to Serangoon Integrated Transport Hub.
		26 September	Designated wheelchair-accessible bus service (WAB).
	2017	12 March	Amended to ply Upp Serangoon Rd and the diverted Upp Aljunied Rd.

Short Trip 100B (2003 - 2008)

Operator	Year	Date	Service changes
	2003	8 September	Introduced as a short-trip service from Ghim Moh Ter to Telok Blangah Rd (HarbourFront Stn) during morning peak hours on weekdays.
	2008	TBC	Discontinued.