History of Services 11 - 20

Service 11 (1971 - 1988)

Operator	Route	Year	Date	Service changes
ABS	Bedok Rd ↔ Tg Pagar Rd (1971 - 1974)	1971	11 April	Introduced between Bedok Rd Ter and Tg Pagar Ter under 1971 Bus Reorganisation.
	Upp Changi Rd 8¼ ms ↔ Tg Pagar Rd (1974 - 1979)	1974	3 February	Amended to Upp Changi Rd 8¼ ms (13.3km) Ter under 1974 Bus Rationalisation.
		1975	2 March	Amended to ply Sims Ave and Lor 1 Geylang towards Upp Changi Rd 13.3 km Ter with the conversion of Geylang Rd to one-way traffic.
	Upp Changi Rd 8¼ ms ↔ New Bridge Rd (1979 - 1980)	1979	28 May	Amended to New Bridge Rd Ter.
			TBC	Relocated to Upp Changi Rd 15.5km Ter.
	Somapah Depot ↔ New Bridge Rd (1980 - 1981)	1980	16 June	Amended to Somapah Depot.
	Somapah ↔ New Bridge Rd (1981 - 1988)	1981	28 June	Amended to Somapah Int.
		1986	7 December	Serves new bus stop before Bedok Sth Ave 3 along Upp East Coast Rd.
		1987	6 June	Amended to relocated New Bridge Rd Ter.
			27 September	Amended to ply the extended Eu Tong Sen St towards Somapah Ter to facilitate the first stage of road expansion along New Bridge Rd.
			1 November	Amended to ply Eu Tong Sen St towards Somapah Ter to facilitate the second stage of road expansion along New Bridge Rd.
		1988	23 October	Integrated with Service 12 and discontinued.

Service 11 (since 1990)

Refer to Bus Service 11 for more information.

Service 12

Operator	Route	Year	Date	Service changes
ABS	Bedok Rd ↔ Commonwealth Ave (1971 - 1974)	1971	11 April	Introduced between Bedok Rd Ter and Commonwealth Ave Ter under 1971 Bus Reorganisation.
	Upp Changi Rd 8¼ ms ↔ Commonwealth Ave (1974 - 1980)	1974	3 February	Amended to Upp Changi Rd 8¼ ms (13.3km) Ter under 1974 Bus Rationalisation.
		1975	2 March	Amended to ply Sims Ave and Lor 1 Geylang towards Upp Changi Rd 13.3 km Ter with the conversion of Geylang Rd to one-way traffic.
			2 November	Amended to temporary bus terminal along Holland Dr with the partial closure of Commonwealth Ave Ter to facilitate the extension of Commonwealth Ave.
			11 December	Amended to ply New Upp Changi Rd, Bedok Wk, Bedok Plain and Bedok Highway.
		1977	17 January	Amended to ply Bedok View, skipping Bedok Wk.
			29 August	Amended back to Commonwealth Ave Ter via Nth Buona Vista Rd.
		1979	TBC	Relocated to Upp Changi Rd 15.5km Ter.
	Somapah Depot ↔ Commonwealth Ave (1980 - 1981)	1980	16 June	Amended to Somapah Depot.
			13 July	Amended to ply Commonwealth Ave with the conversion of Queens Circus to a signalised junction, skipping Queensway and Holland Rd.
			28 December	Amended to ply Upp Changi Rd East, skipping Bedok Rd and Upp Changi Rd.
	Somapah ↔ Commonwealth Ave (1981 - 1982)	1981	28 June	Amended to Somapah Int.
	Somapah ↔ Buona Vista (1982 - 1988)	1982	27 May	Amended to Buona Vista Ter.
		1987	27 September	Amended to ply Nth Canal Rd and Eu Tong Sen St, skipping Upp Circular Rd.
			13 December	Serves new staggered bus stop opposite Peninsula Plaza along Nth Bridge Rd, skipping the bus stop outside St Andrew's Cath.
	Pasir Ris ↔ New Bridge Rd (1988 - 2018)	1988	23 October	Extended to Pasir Ris Ter and shortened to New Bridge Rd Ter.
		1989	10 December	Amended to Pasir Ris Int.
		1990	22 July	Serves additional bus stop outside Ellenborough Mkt along Eu Tong Sen St.
		1993	11 April	Amended to ply Jln Sultan, Victoria St, Hill St and New Bridge Rd, skipping Sth Bridge Rd and Upp Cross St.
		1994	3 July	Amended to ply Kallang Rd and Victoria St, skipping Crawford St, Nth Bridge Rd and Jln Sultan.
		1997	7 December	Amended to ply Upp Pickering St, Sth Bridge Rd and Kreta Ayer Rd with the partial closure of New Bridge Rd to facilitate the construction of Chinatown MRT station on the North East MRT Line.
		2001	TBC	Serves new pair of bus stops outside and opposite Lion Home for Elders along Bedok Sth Rd.
		2002	20 April	Amended to ply the reinstated New Bridge Rd, skipping Upp Pickering St, Sth Bridge Rd and Kreta Ayer Rd.
		2005	5 June	Amended to ply Sims Ave and Sims Way with the partial closure of southbound Mountbatten Rd.
			26 June	Amended to ply Sims Way and Geylang Rd with the partial closure of northbound Mountbatten Rd.
		2006	3 December	Designated wheelchair-accessible bus service (WAB).
		2007	TBC	First bus from New Bridge Rd Ter brought forward to 0600 hrs on weekdays and Saturdays.
		2014	10 August	Serves new bus stop opposite Blk 2 along Mountbatten Rd.
(Current)		2016	18 September	Operations transferred to Go-Ahead Singapore.
		2017	21 October	Serves new pair of bus stops outside Tampines East Stn along Tampines Ave 2.
	Pasir Ris ↔ Kampong Bahru (since 2018)	2018	10 March	Extended to Kg Bahru Ter with the closure of New Bridge Rd Ter.
				First bus from Kg Bahru Ter brought forward to 0555 hrs on weekdays and Saturdays, and 0625 hrs on Sundays and Public Holidays.
			8 April	Serves new pair of bus stops after Somapah Rd and before Simei Rd along Upp Changi Rd East.
		2022	30 October	Temporarily amended to ply Pasir Ris St 11 and Pasir Ris St 12 with the partial closure of Pasir Ris Dr 1 to facilitate the construction of Pasir Ris East MRT station on the Cross Island MRT Line.

Service 12A (1979 - 1984)

Operator	Year	Date	Service changes
	1979	31 December	Introduced between Bedok Sth Ave 3 and North Bridge Rd (Loop) as a peak hour variant, operating daily.
	1981	TBC	Revised to operate on weekdays only.
	1984	2 September	Discontinued.

Service 13

Refer to Bus Service 13 for more information.

Service 13A (1971 - 1974)

Operator	Year	Date	Service changes
ABS	1971	11 April	Introduced between Bedok Rd Ter and Commonwealth Ave Ter under 1971 Bus Reorganisation.
	1974	3 February	Re-numbered Service 14 under 1974 Bus Rationalisation.

Service 14

Refer to Bus Service 14 for more information.

Service 15 (1975 - 1984)

Operator	Route	Year	Date	Service changes
	Marine Terrace ↔ Prince Edward (1975 - 1976)	1975	22 June	Introduced between Marine Terr Ter and Prince Edward Ter.
		1976	15 February	Serves new staggered bus stop outside Overseas Union Finance along Robinson Rd.
			14 March	Serves new staggered bus stop outside The Cenotaph along Connaught Dr, skipping the bus stop opposite Singapore Cricket Club.
	Marine Terrace ↺ Shenton Way (1976 - 1981)		4 July	Extended to loop at Shenton Way from Marine Terr Ter.
		1977	27 March	Amended to ply Marine Terr and Marine Cres towards Shenton Way, and amended to ply Marine Cres and Marine Parade Rd towards Marine Terr Ter with the relocation of Marine Terr Ter opposite Blk 52.
		1978	13 November	Amended to ply Marine Parade Rd and Amber Rd, skipping Joo Chiat Rd and East Coast Rd.
		1979	11 February	Amended to ply the extended Shenton Way, Keppel Rd and Anson Rd, skipping Parsi Rd.
	Marine Parade ↺ Shenton Way (1981 - 1984)	1981	5 July	Amended to Marine Parade Ter.
			11 October	Serves new staggered bus stop outside Tunas Bldg along Anson Rd, skipping the bus stop outside Intl Plaza.
		1984	16 September	Integrated with Service 196 and discontinued.

Service 15 (since 1995)

Operator	Route	Year	Date	Service changes
	Pasir Ris ↔ Eunos (1995 - 1997)	1995	10 September	Introduced between Pasir Ris Int and Eunos Int with the opening of Temasek Polytechnic.
	Pasir Ris ↺ Marine Parade Rd (since 1997)	1997	5 October	Integrated with Service M4 and extended to loop at Marine Parade Rd.
		1998	30 March	Amended to skip Marine Cres with the route extension of Service 13.
			TBC	Serves new pair of bus stops outside East Coast Apts and before St. Patrick's Rd along Telok Kurau Rd.
		2001	TBC	Serves new pair of bus stops outside and opposite Tropica Condo along Tampines Ave 1.
		2002	TBC	First bus brought forward to 0545 hrs on weekdays and Saturdays.
		2009	3 December	Designated wheelchair-accessible bus service (WAB).
		2011	28 August	Amended to ply Jln Tenaga, Bedok Reservoir Rd and Jln Damai with the partial closure of Kaki Bt Ave 1 to facilitate the construction of Kaki Bt MRT station on the Downtown MRT Line.
		2013	10 March	Serves additional bus stop opposite Blk 571 along Pasir Ris Dr 1.
		2016	24 April	Amended to ply the reinstated Kaki Bt Ave 1, skipping Jln Tenaga, Bedok Reservoir Rd and Jln Damai.
(Current)			18 September	Operations transferred to Go-Ahead Singapore.
		2021	11 April	Serves new pair of bus stops outside Blk 524B and opposite Blk 525B along Pasir Ris Dr 8.
			22 December	Amended to ply the realigned Tampines Ave 12, skipping Tampines Ave 9.
		2022	9 October	Serves new pair of bus stops before and opposite Blk 631B and outside Blk 637 CP along Tampines Ave 12.
			30 October	Serves new bus stop opposite Blk 638A along Tampines Ave 12.
			27 November	Serves new pair of bus stops outside and opposite HomeTeamNS Bedok along Bedok Nth Rd.

Short Trip 15A (2000 - 2007)

Operator	Year	Date	Service changes
	2000	TBC	Introduced as a short-trip service from Pasir Ris Int to Tampines Ave 1 (Temasek Poly West G) during morning peak hours on weekdays.
	2007	8 October	Discontinued.

Short Trip 15A (since 2009)

Operator	Route	Year	Date	Service changes
	Pasir Ris → Jln Eunos (since 2009)	2009	27 July	Introduced from Pasir Ris Int to Jln Eunos (Opp Eunos Stn) during morning peak hours on weekdays.
			3 December	Designated wheelchair-accessible bus service (WAB).
		2011	28 August	Amended to ply Jln Tenaga, Bedok Reservoir Rd and Jln Damai with the partial closure of Kaki Bt Ave 1 to facilitate the construction of Kaki Bt MRT station on the Downtown MRT Line.
		2016	24 April	Amended to ply the reinstated Kaki Bt Ave 1, skipping Jln Tenaga, Bedok Reservoir Rd and Jln Damai.
(Current)			18 September	Operations transferred to Go-Ahead Singapore.
		2021	11 April	Serves new bus stop outside Blk 524B along Pasir Ris Dr 8.
			22 December	Amended to ply the realigned Tampines Ave 12, skipping Tampines Ave 9.
		2022	9 October	Serves new bus stop opposite Blk 631B along Tampines Ave 12.
			30 October	Serves new bus stop opposite Blk 638A along Tampines Ave 12.
			27 November	Serves new bus stop outside HomeTeamNS Bedok along Bedok Nth Rd.

Short Trip 15B (2000 - 2007)

Operator	Year	Date	Service changes
	2000	TBC	Introduced as a short-trip service from Jln Eunos (Eunos Stn) to Kaki Bt Ave 1 (Opp Blk 150) during morning peak hours on weekdays.
	2007	8 October	Discontinued.

Service 16

Operator	Route	Year	Date	Service changes
	Marine Terrace ↔ Henderson Rd (1976 - 1977)	1976	2 August	Introduced between Marine Terr Ter and Henderson Rd Ter.
		1977	27 March	Amended to ply Marine Terr and Marine Cres towards Henderson Rd Ter, and Marine Cres, Marine Parade Rd and Marine Terr towards Marine Terr Ter with the relocation of Marine Terr Ter opposite Blk 52.
	Marine Terrace ↔ Telok Blangah Heights (1977 - February 1981)		28 November	Extended to Telok Blangah Hts Ter.
		1979	21 May	Amended to ply Stadium Wk in both directions after 1930 hours daily.
	Marine Terrace ↔ Bukit Merah (February - July 1981)	1981	15 February	Amended to Bt Merah Int.
	Marine Parade ↔ Bukit Merah (July 1981 - 1993)		5 July	Amended to Marine Parade Ter.
		1986	13 April	Amended to ply Stadium Rd, skipping Stadium Wk during the evening diversion into Kallang Pk/Natl Stadium.
		1987	23 February	Amended to Stadium Rd after 1845 hours daily.
		1992	19 July	Amended to ply Orchard Lk due to the closure of Grange Rd to facilitate road expansion works.
		1993	23 May	Amended to ply Stadium Rd permanently under TransitLink Network Integration Exercise Phase 13.
	Bukit Merah ↺ Changi Airport (1993 - 1996)		5 December	Integrated with Service 149, extended to loop at Changi Airport and amended to ply Zion Rd/Kim Seng Rd, Outram Rd and Tiong Bahru Rd under TransitLink Network Integration Exercise Phase 14, skipping River Valley Rd, Delta Rd and Lower Delta Rd.
		1994	TBC	First bus brought forward to 0545 hrs daily.
			29 May	Serves 2 new pairs of bus stops outside The Concourse, outside Golden Mile Twr and outside and opposite Suntec City along Nicoll Highway.
	Bukit Merah ↔ Changi Airport (1996 - 1998)	1996	TBC	Converted to bi-directional service between Bt Merah Int and Changi Airport PTB 1.
	Bukit Merah ↔ Marine Parade (1998 - 2001)	1998	6 September	Shortened to Marine Parade Ter with the conversion of Service 36 to a full day trunk service.
	Bukit Merah ↺ Siglap Rd (2001 - 2007)	2001	16 September	Amended to loop at Siglap Rd from Bt Merah Int with the closure of Marine Parade Ter.
(Current)		2002	8 February	Amended to ply Stadium Wk and Stadium Cres with the partial closure of Stadium Blvd to facilitate the construction of Stadium MRT station on the Circle MRT Line.
			7 July	Skips the bus stop opposite Mandarin Singapore along Orchard Rd.
		2003	TBC	Serves new bus stop outside Victoria Sch along Marine Parade Rd.
		2004	20 April	Amended to ply Mountbatten Rd, Geylang Rd, Kallang Rd, Victoria St, Jln Sultan and Beach Rd to facilitate reinstatement works for the collapsed Nicoll Highway.
			6 December	Amended to ply the reinstated Nicoll Highway, skipping Mountbatten Rd, Geylang Rd, Kallang Rd, Victoria St, Jln Sultan and Beach Rd.
		2005	2 July	Amended to ply Grange Rd with the partial closure of Somerset Rd.
			30 October	Serves new bus stop outside Blk 94 along Zion Rd.
		2006	18 February	Amended to ply Stadium Cres with the full closure of Stadium Blvd to facilitate the construction of Stadium MRT station on the Circle MRT Line.
			19 March	Amended to ply Cassia Lk, Cassia Cres, Guillemard Rd and Guillemard Camp Rd with the partial closure of Old Airport Rd and Dunman Rd to facilitate the construction of Dakota MRT station on the Circle MRT Line.
	Bukit Merah ↔ Bedok (since 2007)	2007	19 August	Extended to Bedok Int.
		2008	29 December	Amended to ply the reinstated Old Airport Rd and Dunman Rd, skipping Cassia Lk, Guillemard Rd and Guillemard Camp Rd.
		2010	29 September	Amended to ply Mountbatten Rd with the closure of Stadium Rd/Stadium Dr to facilitate the construction of the Singapore Sports Hub.
		2011	19 November	Amended to Bedok Temp Int.
			3 December	Designated wheelchair-accessible bus service (WAB).
		2014	30 November	Amended to Bedok Integrated Transport Hub.
		2017	9 April	Amended to ply Still Rd Sth and East Coast Rd to facilitate the construction of Marine Parade MRT station on the Thomson-East Coast MRT Line.
			12 November	Amended to ply the reinstated Marine Parade Rd and Joo Chiat Rd, skipping Still Rd Sth and East Coast Rd.

Short Trip 16A (2001 - 2007)

Operator	Route	Year	Date	Service changes
	Bukit Merah → Siglap Rd (2001 - 2005)	2001	16 September	Introduced from Bt Merah Int to Siglap Rd (Opp Mandarin Gdns), operating after the last bus of Service 16 daily.
		2002	8 February	Amended to ply Stadium Wk with the partial closure of Stadium Blvd to facilitate the construction of Stadium MRT station on the Circle MRT Line.
			7 July	Skips the bus stop opposite Mandarin Singapore along Orchard Rd.
		2004	20 April	Amended to ply Mountbatten Rd, Geylang Rd, Kallang Rd, Victoria St, Jln Sultan and Beach Rd to facilitate reinstatement works for the collapsed Nicoll Highway.
			6 December	Amended to ply the reinstated Nicoll Highway, skipping Mountbatten Rd, Geylang Rd, Kallang Rd, Victoria St, Jln Sultan and Beach Rd.
	Bukit Merah → Marine Parade Rd (2005 - 2007)	2005	25 April	Extended to terminate at Marine Parade Rd (Victoria Sch).
			30 October	Serves new bus stop outside Blk 94 along Zion Rd.
		2006	18 February	Amended to ply Stadium Cres with the full closure of Stadium Blvd to facilitate the construction of Stadium MRT station on the Circle MRT Line.
			19 March	Amended to ply Cassia Lk, Cassia Cres, Guillemard Rd and Guillemard Camp Rd with the partial closure of Old Airport Rd and Dunman Rd to facilitate the construction of Dakota MRT station on the Circle MRT Line.
		2007	19 August	Discontinued with the route extension of Service 16 to Bedok Int.

Short Trip 16B (2005 - 2010)

Operator	Year	Date	Service changes
	2005	17 October	Introduced from Bt Merah Int to Bras Basah Rd (Raffles Hotel) during morning peak hours on weekdays.
		30 October	Serves new bus stop outside Blk 94 along Zion Rd.
	2010	TBC	Discontinued.

Service 16E (1994 - 1997)

Operator	Year	Date	Service changes
	1994	31 January	Introduced between Bt Merah Int and Changi Airport as a peak hour uni-directional semi-express service on weekdays.
	1997	1 December	Re-numbered Service 36.

Service 16M

Operator	Route	Year	Date	Service changes
(Current)	Bedok ↔ Bukit Merah (since 2020)	2020	9 March	Introduced as a supplementary service between Bedok Int and Bt Merah Int during mornings and afternoons on weekdays and mornings on Saturdays, plying an extended route of Service 16 via Jln Bt Merah and Bt Merah Ctrl. Wheelchair-accessible at launch.

Service 17 (1981 - 1984)

Operator	Year	Date	Service changes
	1981	2 February	Introduced between Changi Pt Ter and Prince Edward Ter, operating on weekdays and Saturdays only.
		15 June	Amended to ply Loyang Ave and Loyang Way with the partial closure of Upp Changi Rd.
	1984	8 April	Discontinued.

Service 17 (since 1993)

Operator	Route	Year	Date	Service changes
	Pasir Ris ↔ Bedok (1993 - 2002)	1993	4 April	Introduced between Pasir Ris Int and Bedok Int under TransitLink Network Integration Exercise Phase 12.
		1995	6 February	First bus from Pasir Ris Int brought forward to 0545 hrs daily.
				First bus from Bedok Int brought forward to 0545 hrs daily. Last bus from Bedok Int extended to 2335 hrs daily.
	Pasir Ris ↺ Bedok (2002 - 2016)	2002	7 April	Converted to loop service between Pasir Ris Int and Bedok Int.
				Last bus from Pasir Ris Int extended to 0020 hrs daily.
		2009	5 September	Serves new pair of bus stops outside Blk 231A CP and outside Blk 485 along Pasir Ris Dr 4.
		2011	27 June	Designated wheelchair-accessible bus service (WAB).
			19 November	Amended to loop at Bedok Temp Int.
		2014	30 November	Amended to loop at Bedok Integrated Transport Hub.
(Current)	Pasir Ris ↔ Bedok (since 2016)	2016	18 September	Operations transferred to Go-Ahead Singapore and reverted to bi-directional service.
		2017	21 October	Serves new pair of bus stops outside Tampines East Stn along Tampines Ave 2.
		2022	30 October	Temporarily amended to ply Pasir Ris St 11 and Pasir Ris St 12 with the partial closure of Pasir Ris Dr 1 to facilitate the construction of Pasir Ris East MRT station on the Cross Island MRT Line.

Short Trip 17A

Operator	Route	Year	Date	Service changes
	Bedok → Bedok North Ave 4 (2006 - 2014)	2006	17 April	Introduced from Bedok Int to Bedok Nth Ave 4 (SBST Bedok Bus Pk) during peak hours on weekdays.
		2011	27 June	Designated wheelchair-accessible bus service (WAB).
			19 November	Amended to Bedok Temp Int.
	Bedok North Depot ↺ Bedok (2014 - 2016)	2014	16 November	Converted to a full day service between Bedok Nth Depot and Bedok Temp Int (Loop) under the LTA's Bus Service Enhancement Programme (BSEP).
			30 November	Amended to loop at Bedok Integrated Transport Hub.
(Current)	Bedok → Bedok North Ave 4 (since 2016)	2016	18 September	Operations transferred to Go-Ahead Singapore and reverted to a short trip service from Bedok Int to Bedok Nth Ave 4 (SBST Bedok Bus Pk).

Service 18

Operator	Route	Year	Date	Service changes
	Bedok ↺ Tampines Ave 2 (1982 - 1985)	1982	2 May	Introduced between Bedok Int and Tampines Ave 2 (Loop).
	Bedok ↺ Tampines St 22 (1985 - 1987)	1985	3 November	Amended to loop at Tampines St 22 from Bedok Int.
	Tampines ↺ Bedok (1987 - 2016)	1987	29 November	Extended to start from Tampines Int and loop at Bedok Int, skipping Tampines St 22.
		1988	25 January	First bus brought forward to 0515 hrs on weekdays and Saturdays.
		1999	TBC	Serves new pair of bus stops outside and opposite The Clearwater Condo along Bedok Reservoir Rd.
		2001	TBC	Serves new pair of bus stops opposite Blk 761 and opposite Baywater along Bedok Nth Ave 3.
(Current)		2006	TBC	Skips a pair of removed bus stops outside and opposite Bedok Green Sec Sch along Bedok Nth Ave 3.
		2011	7 March	Designated wheelchair-accessible bus service (WAB).
			19 November	Amended to loop at Bedok Temp Int and amended to ply Bedok Nth Rd and Bedok Nth Ave 2.
		2012	11 March	Serves new bus stop outside Blk 204 along Bedok Nth Int.
		2014	30 November	Amended to loop at Bedok Integrated Transport Hub.
	Tampines Concourse ↺ Bedok (2016 - 2022)	2016	18 December	Extended to Tampines Concourse Int.
		2017	21 October	Amended to ply Tampines St 32, Tampines St 33 and Tampines St 34.
				First bus brought forward to 0505 hrs on weekdays and Saturdays, and 0535 hrs on Sundays and Public Holidays.
		2021	12 December	Serves new pair of bus stops before and after Heartbeat @ Bedok along Bedok Nth St 1.
	Tampines North ↔ Bedok North Depot (since 2022)	2022	27 November	Extended to Tampines Nth Int and Bedok Nth Depot and converted to bi-directional service.

Service 19 (1979 - 1981)

Operator	Route	Year	Date	Service changes
	Siglap Rd ↔ Prince Edward (1979 - 1980)	1979	TBC	Introduced between Siglap Rd and Prince Edward Ter.
	Siglap Rd → Prince Edward (AM) Prince Edward → Siglap Rd (PM) (1980 - 1981)	1980	12 May	Converted to peak-hour one-directional service on weekdays and Saturdays only.
		1981	11 August	Discontinued.

Service 19 (1988 - 1990)

Operator	Route	Year	Date	Service changes
	Bedok ↺ Pasir Ris Dr 6 (1988 - 1989)	1988	19 June	Introduced between Bedok Int and Pasir Ris Dr 6 (Loop).
	Bedok ↔ Pasir Ris (1989 - 1990)	1989	10 December	Amended to Pasir Ris Int.
		1990	11 March	Integrated with Service 4 and discontinued.

Service 19 (since 1994)

Operator	Route	Year	Date	Service changes
	Tampines ↺ Airport Cargo Rd (since 1994)	1994	23 January	Introduced between Tampines Int and Changi Airport Cargo Cplx (Loop) as a day service with the permanent amendment of Service 29 to loop at Changi Village Ter.
(Current)		2003	TBC	Serves new pair of bus stops outside and opposite Loyang Ind Est along Loyang Ave.
		2006	TBC	Last bus extended to 1945 hrs daily.
		2008	TBC	Serves new bus stop outside Changi Beach CP 2 along Nicoll Dr, skipping the bus stop opposite Changi Beach CP 2.
		2011	26 September	Designated wheelchair-accessible bus service (WAB).
		2013	TBC	Last bus extended to 2015 hrs daily.
		2023	26 February	Temporarily amended to ply the bus-only corridor along Loyang Ave and Loyang Way with the partial closure of Loyang Ave to facilitate the construction of Loyang Viaduct and Loyang MRT station on the Cross Island MRT Line, skipping 3 pairs of bus stops along Loyang Ave.

Service 20 (1971 - 1989)

Operator	Route	Year	Date	Service changes
STC	Fidelio St ↔ Commonwealth Ave (1971 - 1973)	1971	11 April	Introduced between Fidelio St Ter and Commonwealth Ave Ter under 1971 Bus Reorganisation.
ABS			6 December	Operations transferred to ABS.
	Chai Chee ↔ Commonwealth Ave (1973 - 1977)	1973	1 July	Amended to Chai Chee Ter.
		1974	8 December	Amended to ply the extended Robinson Rd, skipping Market St.
		1975	2 March	Amended to ply Sims Ave towards Chai Chee Ter with the conversion of Geylang Rd to one-way traffic.
		1976	15 February	Serves new staggered bus stop between Bank of India and Hong Leong Holdings along Robinson Rd.
	Chai Chee ↔ Ghim Moh (1977 - 1985)	1977	7 March	Extended to Ghim Moh Ter.
			17 May	Amended to ply Commonwealth Ave Extension.
		1978	15 January	Amended to ply Jln Sultan, skipping Sumbawa Rd.
		1979	11 February	Amended to ply the extended Shenton Way towards Ghim Moh Ter, skipping Parsi Rd and Anson Rd.
			14 October	Amended to ply Sims Ave East towards Chai Chee Ter with the conversion of Changi Rd to one-way traffic.
		1981	11 October	Serves new staggered bus stop outside Tunas Bldg along Anson Rd, skipping the bus stop outside Intl Plaza.
	Bedok ↔ Ghim Moh (1985 - 1989)	1985	8 September	Extended to Bedok Int with the closure of Chai Chee Ter.
		1988	3 January	Serves new staggered bus stop opposite Treasury Bldg along Shenton Way, skipping the bus stop opposite Marina Hse.
		1989	5 November	Integrated with Service 100 and discontinued.

Service 20 (1994 - 2000)

Operator	Year	Date	Service changes
	1994	TBC	Introduced between Sims Pl Ter and St. Wilfred Rd (Loop).
	2000	27 November	Integrated with Service 125 and discontinued.

Service 20 (since 2013)

Operator	Route	Year	Date	Service changes
(Current)	Tampines ↺ Changi Business Park Ctrl 2 (since 2013)	2013	9 June	Introduced between Tampines Int and Changi Business Pk Ctrl 2 (Loop) under the LTA's Bus Service Enhancement Programme (BSEP), operating between 0600 hrs and 2330 hrs daily.
			30 September	Designated wheelchair-accessible bus service (WAB).
		2015	20 December	Serves new pair of bus stops outside and opposite Changi City Pt along Changi South Ave 2.
		2017	21 October	Amended to ply Somapah Rd and Changi Sth Ave 1, skipping Upp Changi Rd East and Xilin Ave.
		2018	10 June	Serves new pair of bus stops outside and opposite The Eightrium along Changi Sth Ave 1.
		2021	26 December	Serves new bus stop after Changi Business Park Crescent along Changi Business Pk Vista.

Short Trip 20A

Operator	Route	Year	Date	Service changes
(Current)	Simei St 1 → Changi South Ave 1 (since 2024)	2024	27 May	Introduced from Simei St 1 (Blk 148) to Changi Sth Ave 1 (Expo Stn Exit B) during morning peak hours on Weekdays. Wheelchair-accessible at launch.