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

Refer to Bus Service 12 for more information.

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)

Refer to Bus Service 15 for more information.

Service 16

Refer to Bus Service 16 for more information.

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

Refer to Bus Service 16M for more information.

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)

Refer to Bus Service 17 for more information.

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.