History of Services 180 - 189

Service 180

1^st Generation (1971)

Operator	Route	Year	Date	Service changes
United Bus Company	Bt Timah ↔ Prince Edward	1971	11 April	Introduced between Bt Timah Ter and Prince Edward Ter under 1971 Bus Reorganisation.
			9 May	Integrated with Service 180A, amended to ply Stamford Rd, Waterloo St and Bras Basah Rd and re-numbered Service 180/180A.

2^nd Generation (1974 - 1991)

Operator	Route	Year	Date	Service changes
	Upp Bt Timah Rd ↔ Tg Pagar Rd	1974	3 February	Re-numbered from Service 180/180A as a service between Upp Bt Timah Rd Ter and Tg Pagar Ter under 1974 Bus Rationalisation.
			8 December	Amended to ply Cecil St, skipping Robinson Rd.
		1975	19 July	Amended to ply Coleman St and Hill St, skipping Stamford Rd.
	Marsiling ↔ Tg Pagar Rd	1976	11 January	Extended to Admiralty Rd Ter.
		1979	11 February	Amended to ply the extended Shenton Way, Rambau St and Trafalgar St towards Tg Pagar Ter, skipping Parsi Rd.
	Marsiling ↔ Anson Rd		1 August	Amended to Anson Rd Ter.
			25 November	Amended to ply Pickering St and Church St, skipping Nth Canal Rd and Market St.
			30 December	Amended to ply Jln Anak Bt towards Anson Rd Ter with the partial conversion of Upp Bt Timah Rd to one-way traffic.
		1983	7 August	Operations transferred to TIBS.
	Marsiling ↔ World Trade Ctr	1985	13 January	Extended to World Trade Ctr Ter.
		1990	19 August	Amended to ply Bt Timah Rd, Sungei Rd, Bencoolen St, Orchard Rd, Penang Rd and Clemenceau Ave (towards World Trade Ctr Ter) / Orchard Rd, Dhoby Ghaut, Selegie Rd and Bt Timah Rd due to the partial closure of Clemenceau Ave to facilitate Phase 2 of the construction of CTE.
		1991	6 January	Discontinued under TransitLink Network Integration Exercise Phase 1.

3^rd Generation (since 1996)

Operator	Route	Year	Date	Service changes
(Current) Known as prior to 10 May 2004	Bukit Panjang ↔ Boon Lay	1996	10 March	Re-numbered from Service 951 as a service between Bt Panjang Ter and Boon Lay Int under Woodlands MRT Rationalisation.
			TBC	First bus from Bt Panjang Ter brought forward to 0530 hrs daily.
		1999	26 December	Amended to Bt Panjang Int.
				First bus from Bt Panjang Int brought forward to 0520 hrs on weekdays and Saturdays.
				First bus from Boon Lay Int brought forward to 0550 hrs on weekdays and Saturdays.
		2006	18 June	Amended to Boon Lay Temp Int.
		2009	27 December	Amended to Boon Lay Integrated Transport Hub.
	180Boon Lay ↺ Bukit Panjang 180ABoon Lay → Bukit Panjang Rd	2012	16 December	Amended to loop at Petir Rd from Boon Lay Int with the closure of Bt Panjang Int.
				180AIntroduced from Boon Lay Int to Bt Panjang Rd (Blk 183) during evening peak hours on weekdays and after the last bus of Service 180 daily.
		2017	23 April	Serves relocated bus stop before PIE along Bt Batok Rd.
			16 July	Designated wheelchair-accessible bus service (WAB).
			4 September	Serves the bus stop outside Bt Panjang Stn along Upp Bt Timah Rd, skipping the removed bus stop along Petir Rd.
		2018	25 February	Amended to loop at Bt Panjang Int.

Service 180/180A

Operator	Route	Year	Date	Service changes
United Bus Company	Bt Timah ↔ Prince Edward	1971	9 May	Re-numbered from Service 180 between Bt Timah Ter and Prince Edward Ter.
	Upp Bt Timah Rd ↔ Tg Pagar Rd	1974	3 February	Extended to Upp Bt Timah Rd Ter, extended to Tg Pagar Ter, amended to skip Stamford Rd, Waterloo St and Bras Basah Rd and re-numbered Service 180 under 1974 Bus Rationalisation.

Service 180A

Operator	Route	Year	Date	Service changes
United Bus Company	Bt Timah ↺ Stamford Rd	1971	11 April	Introduced between Bt Timah Ter and Stamford Rd (Loop) under 1971 Bus Reorganisation.
			9 May	Integrated with Service 180 and discontinued.

Service 181

1^st Generation (1971 - 1998)

Operator	Route	Year	Date	Service changes
United Bus Company	Bukit Timah ↔ Commonwealth Ave	1971	11 April	Introduced between Bt Timah Ter and Commonwealth Ave Ter under 1971 Bus Reorganisation.
			28 September	Amended to ply the extended Ganges Ave towards Bt Timah Ter.
	Upp Bt Timah Rd ↔ Commonwealth Ave		8 November	Extended to Upp Bt Timah Rd Ter.
		1972	11 June	Amended to ply Upp Cross St with the partial conversion of Havelock Rd to one-way traffic, skipping Upp Hokien St.
	Upp Bt Timah Rd ↔ Crawford St	1974	3 February	Extended to Crawford St Ter under 1974 Bus Rationalisation.
		1979	30 December	Amended to ply Jln Anak Bt towards Crawford St Ter with the partial conversion of Upp Bt Timah Rd to one-way traffic.
	Woodlands Ctr ↔ Crawford St	1980	14 December	Extended to Woodlands Town Ter.
		1981	29 November	Amended to Woodlands Int.
		1983	4 September	Operations transferred to TIBS.
		1987	27 September	Amended to ply the extended Eu Tong Sen St towards Crawford St Ter to facilitate the first stage of road expansion along New Bridge Rd.
			1 November	Amended to ply Eu Tong Sen St towards Crawford St Ter to facilitate the second stage of road expansion along New Bridge Rd.
			13 December	Serves new staggered bus stop opposite Peninsula Plaza along Nth Bridge Rd, skipping the bus stop outside St Andrew's Cath.
		1988	28 February	Revised to operate on weekdays and Saturdays only with the introduction of Service 181#.
			20 March	Amended to ply Upp Cross St and New Bridge Rd, skipping Neil Rd.
		1990	22 July	Serves additional bus stop outside Ellenborough Mkt along Eu Tong Sen St.
	Woodlands ↔ Crawford St	1996	4 February	Amended to Woodlands Reg Int.
		1997	TBC	First bus from Woodlands Reg Int brought forward to 0530 hrs.
			TBC	Serves additional bus stop after Jln Bt Merah along Kg Bahru Rd.
			7 December	Amended to ply Sth Bridge Rd, Neil Rd and Cantonment Rd with the partial closure of New Bridge Rd to facilitate the construction of Chinatown MRT station on the North East MRT Line.
		1998	27 December	Extended to Lor 1 Geylang Ter and re-numbered Service 961.

2^nd Generation (since 2005)

Operator	Route	Year	Date	Service changes
	Boon Lay ↺ Jurong West Ave 3	2005	9 January	Introduced between Boon Lay Int and Jurong West Ave 3 (Loop), operating between 0600 hrs and 2400 hrs daily.
		2006	18 June	Amended to Boon Lay Temp Int.
		2008	TBC	Last bus extended to 0030 hrs daily.
			15 June	Serves new pair of bus stops outside Blk 670A and outside Blk 678D along Jurong West St 64.
		2009	27 December	Amended to Boon Lay Integrated Transport Hub.
		2010	18 October	Designated wheelchair-accessible bus service (WAB).
		2013	TBC	Last bus extended to 0040 hrs daily.
(Current)		2024	1 September	Operations transferred to SMRT Buses.

Service 181#

Operator	Route	Year	Date	Service changes
	Woodlands Ctr ↔ Crawford St	1988	28 February	Introduced between Woodlands Int and Crawford St Ter as an alternate route of Service 181 via Marina Centre, operating on Sundays and Public Holidays.
			20 March	Amended to ply Upp Cross St and New Bridge Rd, skipping Neil Rd.
		1990	22 July	Serves additional bus stop outside Ellenborough Mkt along Eu Tong Sen St.
	Woodlands ↔ Crawford St	1996	4 February	Amended to Woodlands Reg Int.
		1997	TBC	Serves additional bus stop after Jln Bt Merah along Kg Bahru Rd.
			7 December	Amended to ply Sth Bridge Rd, Neil Rd and Cantonment Rd with the partial closure of New Bridge Rd to facilitate the construction of Chinatown station on the North East Line.
		1998	27 December	Extended to Lor 1 Geylang Ter and re-numbered Service 961#.

Service 181M

Operator	Route	Year	Date	Service changes
	Boon Lay ↺ Jurong West St 23	2016	21 March	Introduced between Boon Lay Int and Jurong West St 23 (Loop) as a morning peak hour service on weekdays (except school holidays). Wheelchair-accessible bus service (WAB) at launch. .
(Current)		2024	1 September	Operations transferred to SMRT Buses.

Service 182

1^st Generation (1971 - 1996)

Operator	Route	Year	Date	Service changes
United Bus Company	Bukit Timah ↔ Jln Besi	1971	11 April	Introduced between Bt Timah Ter and Jln Besi Ter under 1971 Bus Reorganisation.
	Bukit Timah ↔ Benoi Rd		TBC	Extended to Benoi Rd Ter.
		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.
	Bukit Timah ↺ Shenton Way	1974	3 February	Amended to loop at Shenton Way from Bt Timah Ter under 1974 Bus Rationalisation.
			24 February	Amended to ply Grange Rd, Orchard Blvd and Paterson Rd towards Bt Timah Ter with the conversion of Orchard Rd to one-way traffic.
			8 December	Amended to ply Cecil St, skipping Robinson Rd.
	Marsiling ↔ New Bridge Rd	1976	6 June	Extended to Admiralty Rd Ter and amended to New Bridge Rd Ter.
		1979	30 December	Amended to ply Jln Anak Bt towards New Bridge Rd Ter with the partial conversion of Upp Bt Timah Rd to one-way traffic.
		1983	7 August	Operations transferred to TIBS.
		1987	6 June	Amended to the relocated New Bridge Rd Ter.
			27 September	Amended to ply the extended Eu Tong Sen St towards Marsiling Ter to facilitate the first stage of road expansion along New Bridge Rd.
			1 November	Amended to ply Eu Tong Sen St towards Marsiling Ter to facilitate the second stage of road expansion along New Bridge Rd.
			13 December	Serves new staggered bus stop outside Orchard Stn along Orchard Blvd, skipping the bus stop opposite Orchard Stn.
				Serves new bus stop outside Newton Stn along Scotts Rd.
		1988	20 March	Amended to ply Upp Cross St and New Bridge Rd, skipping Neil Rd.
		1992	19 July	Amended to ply Orchard Lk due to the closure of Grange Rd to facilitate road expansion works.
	Marsiling ↔ Shenton Way	1993	3 January	Amended to Shenton Way Ter under TransitLink Network Integration Exercise Phase 7.
		1995	7 May	Amended to ply Orchard Turn.
	Woodlands ↔ Shenton Way	1996	4 February	Amended to Woodlands Reg Int.
			10 March	Discontinued under Woodlands MRT Rationalisation.

2^nd Generation (since 1998)

Operator	Route	Year	Date	Service changes
Known as prior to 1 November 2001	Jurong East ↔ Tuas	1998	19 July	Introduced between Jurong East Int and Tuas Ter, calling at Tuas Checkpoint at selected timings only.
	Boon Lay ↔ Tuas	2001	25 February	Shortened to Boon Lay Int.
	Boon Lay ↺ Tuas South Ave 9	2002	26 May	Integrated with Service 183, extended to loop at Tuas Sth Ave 9 and amended to ply Jurong West St 64, Boon Lay Way, Upp Jurong Rd and PIE, skipping Jln Boon Lay.
		2004	19 January	Serves all bus stops along Upp Jurong Rd.
		2005	7 August	Serves new pair of bus stops outside and opposite Sin Lian Heng Construction along Tuas South Ave 3.
		2006	18 June	Amended to Boon Lay Temp Int.
		2007	25 November	Serves 2 new pairs of bus stops before Tuas Sth Ave 2, outside LTH Distripark, before and after Tuas Sth Ave 2 along Tuas Sth Ave 3.
	Boon Lay ↺ Tuas South Ave 9	2009	27 December	Amended to Boon Lay Integrated Transport Hub.
		2013	30 September	Designated wheelchair-accessible bus service (WAB).
	Joo Koon ↺ Tuas South Ave 9	2015	28 November	Shortened to Joo Koon Integrated Transport Hub and serves all bus stops along Tuas West Dr.
		2016	4 January	First bus brought forward to 0545 hrs daily.
		2022	13 February	Amended to ply new road towards Tuas Sth Ave 9, skipping the Tuas roundabout.
		2024	24 March	Serves new bus stop outside Singapore Rail Test Centre along Jln Ahmad Ibrahim.
(Current)			15 September	Operations transferred to SMRT Buses.

Service 182X/182M

Operator	Route	Year	Date	Service changes
Known as prior to 1 November 2001	182XJurong East ↔ Tuas	1998	19 July	182XIntroduced between Jurong East Int and Tuas Ter as an alternate route of Service 182 during off peak periods, skipping Tuas Checkpoint in both directions.
	182XBoon Lay ↔ Tuas	2001	25 February	Shortened to Boon Lay Int.
				Last bus from Tuas Ter brought forward to 2300 hrs daily.
	182XBoon Lay ↺ Tuas South Ave 9	2002	26 May	Integrated with Service 183, extended to loop at Tuas Sth Ave 9 and amended to ply Jurong West St 64, Boon Lay Way, Upp Jurong Rd and PIE, skipping Jln Boon Lay.
		2004	19 January	Serves all bus stops along Upp Jurong Rd.
		2005	7 August	Serves new pair of bus stops outside and opposite Sin Lian Heng Construction along Tuas South Ave 3.
		2006	18 June	Amended to Boon Lay Temp Int.
	182MBoon Lay ↺ Tuas South Ave 9	2008	28 January	182X 182MRe-numbered as Service 182M.
			11 February	Serves 2 new pairs of bus stops before Tuas Sth Ave 2, outside LTH Distripark, before and after Tuas Sth Ave 2 along Tuas Sth Ave 3.
		2009	27 December	Amended to Boon Lay Integrated Transport Hub.
		2013	26 August	Amended to call at Tuas Checkpoint towards Boon Lay Int only.
			30 September	Designated wheelchair-accessible bus service (WAB).
	182MJoo Koon ↺ Tuas South Ave 9	2015	28 November	Shortened to Joo Koon Integrated Transport Hub and serves all bus stops along Tuas West Dr.
		2022	13 February	Amended to ply new road towards Tuas Sth Ave 9, skipping the Tuas roundabout.
		2024	24 March	Serves new bus stop outside Singapore Rail Test Centre along Jln Ahmad Ibrahim.
(Current)			15 September	Operations transferred to SMRT Buses.
	182MJoo Koon ↺ Tuas South Ave 9 182ATuas West Dr → Tuas Sth Ave 3		29 December	182AIntroduced from Tuas West Drive (Opp Tuas Link Stn) to Tuas South Ave 3 (Bef Tuas Sth Ave 4), operating only on Sunday and Public Holiday nights. Wheelchair-accessible bus service (WAB) at launch.

Service 183

1^st Generation (1974 - 1988)

Operator	Route	Year	Date	Service changes
	Benoi Rd ↔ South Canal	1974	3 February	Introduced between Benoi Rd Ter and Sth Canal Ter under 1974 Bus Rationalisation.
		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.
	Jurong ↔ New Bridge Rd	1978	1 June	Amended to Jurong Int and amended to New Bridge Rd Ter.
		1987	6 April	Skips removed bus stop before College Rd along Outram Rd.
			6 June	Amended to the relocated New Bridge Rd Ter.
			1 November	Amended to ply Eu Tong Sen St towards Jurong Int to facilitate the second stage of road expansion along New Bridge Rd.
		1988	11 January	Serves merged bus stop along Ayer Rajah Rd.
			18 December	Discontinued.

2^nd Generation (1998 - 2002)

Operator	Route	Year	Date	Service changes
Known as prior to 1 November 2001	Tuas ↺ Tuas South Ave 6	1998	19 July	Introduced between Tuas Ter and Tuas Sth Ave 6 (Loop).
	Tuas ↺ Tuas South Ave 9	2001	11 February	Extended to loop at Tuas Sth Ave 9, skipping Tuas Sth Ave 6.
		2002	26 May	Integrated with Service 182/182X and discontinued.

3^rd Generation (since 2004)

Operator	Route	Year	Date	Service changes
	Jurong East ↺ Clementi Rd	2004	22 August	Introduced between Jurong East Int and Clementi Rd (Loop), operating between 0600 hrs and 2330 hrs daily.
		2005	3 October	Extended to loop at Science Pk Rd.
	183Jurong East ↺ Science Park Rd 183ACommonwealth Ave West → Science Pk Rd		12 December	183AIntroduced between Commonwealth Ave West (Clementi Stn) and Science Pk Rd (Loop) during morning peak hours on weekdays.
		2008	2 December	Designated wheelchair-accessible bus service (WAB).
	183Jurong East ↺ Science Park Rd 183AJurong East → Science Pk Rd	2009	TBC	183AExtended to start from Jurong East Int.
	183Jurong East ↺ Science Park Rd 183AJurong East → Science Pk Rd 183BJurong East → Toh Tuck Ave	2010	16 August	183BIntroduced from Jurong East Int to Toh Tuck Ave (Ulu Pandan R.I. Plant) during morning peak hours on weekdays. Wheelchair-accessible bus service (WAB) at launch.
		2011	17 December	Amended to Jurong East Temp Int.
	183Jurong East ↺ Science Park Rd 183BJurong East → Toh Tuck Ave	2012	TBC	183ADiscontinued.
(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 184

1^st Generation (1977 - 1990)

Operator	Route	Year	Date	Service changes
	Telok Blangah Way ↔ Boon Lay Gardens	1977	25 November	Introduced between Telok Blangah Way Ter and Boon Lay Gdns Ter.
	Telok Blangah Way ↔ Jurong	1978	1 June	Amended to Jurong Int.
	Bukit Merah ↔ Jurong	1980	28 September	Amended to Bt Merah Int.
		1981	15 February	Amended to skip Telok Blangah Way and Telok Blangah Cres in both directions.
		1987	2 August	Amended to ply West Coast Highway, skipping Upp Ayer Rajah Rd and Clementi Rd.
		1990	1 July	Integrated with Service 176 and discontinued with the opening of Boon Lay Int.

2^nd Generation (since 1994)

Operator	Route	Year	Date	Service changes
	Bukit Panjang ↺ Commonwealth Ave West	1994	3 July	Introduced between Bt Panjang Ter and Commonwealth Ave West (Loop).
(Current) Known as prior to 10 May 2004		1995	2 July	Operations transferred to Trans Island Bus Services.
		1998	TBC	First bus brought forward to 0545 hrs on weekdays.
		1999	26 December	Amended to Bt Panjang Int.
	184Bukit Panjang ↺ Commonwealth Ave West 184ABukit Panjang → Clementi Rd	2000	TBC	184AIntroduced from Bt Panjang Int to Clementi Rd (Opp Ngee Ann Poly) during morning peak hours on weekdays.
	Bukit Panjang ↺ Commonwealth Ave West	2003	TBC	184ADiscontinued.
			12 October	Serves bus stop opposite Bt Timah Plaza along Jln Anak Bt with the removal of the bus stop under the PIE Flyover.
		2010	23 May	Skips temporarily closed bus stop outside Assumption Voc Inst along Upp Bt Timah Rd to facilitate the construction of Cashew station along the Downtown Line.
		2011	3 July	Serves additional pair of bus stops opposite Min of Defence and before Cashew Rd along Upp Bt Timah Rd.
		2012	16 December	Amended to start from and terminate at Bt Panjang Rd with the opening of Bt Panjang Temp Bus Pk and the closure of Bt Panjang Int.
		2015	1 March	Serves reinstated bus stop outside Assumption Pathway Sch along Upp Bt Timah Rd, skipping a pair of bus stops opposite Min of Defence and before Cashew Rd.
		2017	4 September	Serves additional pair of bus stops outside and opposite Ten Mile Junction Stn along Woodlands Rd.
			17 December	Designated wheelchair-accessible bus service (WAB).
	Gali Batu ↺ Commonwealth Ave West	2021	23 January	Extended to Gali Batu Ter, serving 2 additional pairs of bus stops after KJE Slip Rd, Blk 632 CP, opposite Blk 632 CP and opposite Blk 635A along Woodlands Rd.
				First bus from Woodlands Rd (Aft KJE Slip Rd) brought forward to 0540 hrs on Weekdays and Saturdays, and 0555 hrs on Sundays and Public Holidays.
				Last bus from Woodlands Rd (Aft KJE Slip Rd) extended to 2305 hrs daily.

Service 185

1^st Generation (1979 - 1985)

Operator	Route	Year	Date	Service changes
	Clementi ↺ North Buona Vista Rd	1979	16 July	Introduced between Clementi Ter and Nth Buona Vista Rd (Loop).
	Clementi ↺ Bt Merah Ctrl		25 November	Extended to loop at Bt Merah Ctrl.
	Clementi ↺ Bukit Merah	1980	28 September	Extended to loop at Bt Merah Int.
			16 November	Amended to Clementi Int.
		1981	21 June	Amended to skip Nepal Circus towards Bt Merah Int.
		1985	28 April	Integrated with Service 92 and discontinued.

2^nd Generation (1988 - 2003)

Operator	Route	Year	Date	Service changes
	Choa Chu Kang ↔ Shenton Way	1988	31 July	Introduced between Choa Chu Kang Ter and Shenton Way Ter.
			25 August	Amended to ply Choa Chu Kang Ave 1 with the completion of the road junction between Teck Whye Ave and Choa Chu Kang Ave 1.
		1989	28 May	Amended to ply Commonwealth Ave.
		1990	10 March	Extended to interim terminal along Choa Chu Kang Ave 4.
			8 April	Amended to Choa Chu Kang Int.
		1991	28 April	Amended to ply Bt Batok East Ave 2 under TransitLink Network Integration Exercise Phase 4, skipping Bt Batok East Ave 3.
	Choa Chu Kang ↺ Jln Anak Bt	1993	3 January	Shortened to loop at Jln Anak Bt from Choa Chu Kang Int with the introduction of Service 186 under TransitLink Network Integration Exercise Phase 11.
		1997	TBC	Serves new bus stop outside Lot 1 Shoppers' Mall along Choa Chu Kang Ave 4.
		1999	29 August	Operations transferred to TIBS.
				First bus brought forward to 0530 hrs on Sundays & Public Holidays.
		2003	TBC	Serves new bus stop outside Goh & Goh Bldg along Jln Jurong Kechil.
			27 July	Integrated with Service 989 to form Service 985 and discontinued.

3^rd Generation (since 2006)

Operator	Route	Year	Date	Service changes
	Soon Lee Bus Pk ↔ Buona Vista	2006	26 December	Introduced between Soon Lee Bus Pk and Buona Vista Ter, operating between 0600 hrs and 2300 hrs from Soon Lee Bus Pk and Buona Vista Ter daily.
		2007	5 August	Serves new pair of bus stops outside and opposite Soon Lee Depot along Soon Lee Rd.
		2008	14 July	Designated wheelchair-accessible bus service (WAB).
			29 December	Last bus from Soon Lee Bus Pk extended to 2315 hrs daily.
		2009	18 May	First bus from Soon Lee Bus Pk brought forward to 0545 hrs daily.
(Current)		2024	15 September	Operations transferred to SMRT Buses.

Service 186

1^st Generation (1977 - 1989)

Operator	Route	Year	Date	Service changes
	Clementi ↔ Tg Pagar Rd	1977	7 November	Introduced between Clementi Ter and Tg Pagar Rd Ter.
		1978	5 June	Amended to relocated roadside terminus along Clementi Ave 3 via Commonwealth Ave West, skipping Clementi Ave 2.
	Clementi ↔ Anson Rd	1979	1 August	Amended to Anson Rd Ter.
		1980	16 November	Amended to Clementi Int.
	Clementi ↔ Prince Edward	1985	27 January	Amended to Prince Edward Ter with the closure of Anson Rd Ter.
	Clementi ↔ Shenton Way	1987	28 June	Amended to Shenton Way Ter.
		1988	8 March	Amended to ply Clementi Ave 3 with the abolition of right turning from Clementi Ave 3 to Commonwealth Ave West.
		1989	27 August	Integrated with Service 145 and discontinued.

2^nd Generation (since 1993)

Operator	Route	Year	Date	Service changes
(Current) Known as prior to 1 November 2001	Shenton Way ↺ Farrer Rd	1993	3 January	Introduced between Shenton Way Ter and Farrer Rd (Loop) under TransitLink Network Integration Exercise Phase 11.
	Shenton Way ↔ St. Michael's		4 April	Extended to St. Michael's Ter under TransitLink Network Integration Exercise Phase 12.
		2000	TBC	Serves new bus stop after Shenton Way along Palmer Rd.
		2004	TBC	Skips removed bus stop outside Nanyang Pr Sch along Farrer Rd.
		2011	4 September	Serves new bus stop outside Botanic Gdns Stn along Bt Timah Rd.
		2012	30 September	Designated wheelchair-accessible bus service (WAB).
		2014	27 April	Serves new bus stop outside Queens Condo along Commonwealth Ave.
		2017	25 June	Amended to the relocated Shenton Way Ter.
		2023	23 July	Amended to ply temporary slip road and Mt Pleasant Rd towards St Michael's Ter with the temporary closure of slip road to PIE Exit 17D.

Service 187

1^st Generation (1981 - 1983)

Operator	Route	Year	Date	Service changes
	Bt Merah ↺ Empress Pl	1981	15 February	Introduced as a day service between Bt Merah Int and Empress Pl (Loop).
			19 May	Converted to peak hour service on weekdays and Saturdays.
		1983	14 November	Discontinued.

2^nd Generation (since 1988)

Operator	Route	Year	Date	Service changes
	Bt Panjang ↔ Jurong	1988	10 July	Introduced between Bt Panjang Ter and Jurong Int.
		1989	10 April	First bus from Bt Panjang Ter brought forward to 0530 hrs on weekdays and Saturdays.
		1990	7 January	Serves new pair of bus stops outside and opposite Bt Batok Driving Ctr along Bt Batok West Ave 5.
	Bt Panjang ↔ Boon Lay		1 July	Amended to Boon Lay Int.
(Current) Known as prior to 10 May 2004		1995	17 September	Operations transferred to Trans Island Bus Services.
	Woodlands ↔ Boon Lay	1996	10 March	Extended to Woodlands Reg Int under Woodlands MRT Rationalisation.
		1997	TBC	First bus from Boon Lay Int brought forward to 0550 hrs on weekdays and Saturdays.
		1998	TBC	First bus from Boon Lay Int brought forward to 0540 hrs on weekdays and Saturdays.
	187Woodlands ↔ Boon Lay 187ABoon Lay → Bt Batok Central	2003	25 August	187AIntroduced from Boon Lay Int to Bt Batok Ctrl (Blk 628) during morning peak hours on weekdays.
	Woodlands ↔ Boon Lay	2004	TBC	187ADiscontinued.
		2006	30 April	Serves new pair of bus stops outside Blk 336 and opposite Blk 334 along Bt Batok West Ave 7.
			18 June	Amended to Boon Lay Temp Int.
		2009	27 December	Amended to Boon Lay Integrated Transport Hub.
		2012	29 April	Designated wheelchair-accessible bus service (WAB).
		2016	12 March	Amended to Woodlands Temp Int.
		2021	13 June	Amended to Woodlands Integrated Transport Hub.

Service 188

1^st Generation (1977 - 1987)

Operator	Route	Year	Date	Service changes
	Ulu Pandan ↺ Shenton Way	1977	17 October	Introduced between Ulu Pandan Ter and Shenton Way (Loop), replacing the deleted sectors of Service 94.
		1979	11 February	Amended to ply the extended Shenton Way towards Ulu Pandan Ter, skipping Parsi Rd and Anson Rd.
		1980	20 January	Amended to ply Spottiswoode Pk Rd with the partial conversion of Cantonment 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.
		1987	6 April	Skips removed bus stop before College Rd along Outram Rd.
			5 July	Discontinued.

2^nd Generation (1988 - 1991)

Operator	Route	Year	Date	Service changes
	Jurong ↺ Jurong West St 91	1988	10 July	Introduced between Jurong Int and Jurong West St 91 (Loop).
		1989	17 December	Amended to ply Jurong West St 72 and Jurong West Ave 5, skipping Pioneer Rd Nth.
	Corporation Dr ↺ Jurong West St 91	1990	1 July	Amended to start/terminate at Corporation Dr with the opening of Boon Lay Int.
		1991	20 January	Discontinued under TransitLink Network Integration Exercise Phase 2.

3^rd Generation (since 1999)

Operator	Route	Year	Date	Service changes
	Choa Chu Kang ↔ HarbourFront	1999	7 March	Introduced between Choa Chu Kang Int and World Trade Ctr Ter.
(Current) Known as prior to 10 May 2004			26 December	Operations transferred to TIBS.
		2002	TBC	Skips removed bus stop opposite ITE Pasir Panjang along Telok Blangah Rd.
			TBC	First bus from HarbourFront Int revised to 0630 hrs on Sundays and Public Holidays.
		2006	30 April	Serves new pair of bus stops outside Blk 336 and opposite Blk 334 along Bt Batok West Ave 7.
	188Choa Chu Kang ↔ HarbourFront 188AChoa Chu Kang → Choa Chu Kang Gr	2010	5 July	188AIntroduced from Choa Chu Kang Int to Choa Chu Kang Gr (ITE College West) during morning peak hours on weekdays.
	Choa Chu Kang ↔ HarbourFront		13 September	188ADiscontinued.
		2015	22 March	Designated wheelchair-accessible bus service (WAB).
		2018	16 December	Amended to new Choa Chu Kang Int.
		2024	28 January	Serves relocated bus stop after Clementi Swim Cplx along AYE.

Service 189

Operator	Route	Year	Date	Service changes
	Commonwealth Ave ↔ South Canal	1974	3 February	Re-numbered from Service 193A as a service between Commonwealth Ave Ter and Sth Canal Ter under 1974 Bus Rationalisation.
			8 December	Amended to ply Cecil St, skipping Robinson Rd.
		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.
		1977	17 May	Amended to ply Commonwealth Ave Extension and Nth Buona Vista Rd towards Commonwealth Ave Ter.
			29 August	Amended to ply Holland Ave, Holland Dr and Nth Buona Vista Rd towards Commonwealth Ave Ter.
		1978	22 January	Amended to ply Commonwealth Ave, Queensway, Commonwealth Dr, Commonwealth Ave and Queen's Circus with the conversion of Farrer Circus into a traffic-signal controlled junction.
	Commonwealth Ave ↺ Empress Pl	1979	15 January	Amended to loop at Empress Pl from Commonwealth Ave Ter.
				Amended to ply Jln Bt Merah, Kg Bahru Rd and New Bridge Rd/Neil Rd, skipping Commonwealth Dr, Tiong Bahru Rd and Outram Rd.
			11 February	Amended to ply the extended Shenton Way towards Commonwealth Ave Ter, skipping Parsi Rd and Anson Rd.
		1980	20 January	Amended to ply Spottiswoode Pk Rd with the partial conversion of Cantonment Rd to one-way traffic.
	Buona Vista ↺ Empress Pl	1982	27 May	Amended to Buona Vista Ter.
	Bukit Batok ↔ Marina Ctr	1985	24 November	Extended to Bt Batok Ter and Marina Ctr Ter.
		1986	30 November	Amended to the relocated Marina Ctr Ter along Raffles Blvd.
		1987	27 September	Amended to Bt Batok Int.
			1 November	Amended to ply Eu Tong Sen St towards Marina Ctr Ter to facilitate the second stage of road expansion along New Bridge Rd.
	Bukit Batok ↺ Clementi West St 2	1991	28 April	Shortened to loop at Clementi West St 2 from Bt Batok Int, integrated with Service 366 and amended to ply Bt Batok Ctrl, Bt Batok Ave 1, Bt Batok East Ave 6 and Bt Batok St 23 under TransitLink Network Integration Exercise Phase 4.
	Bukit Batok ↺ West Coast Ferry Ter	1995	6 May	Extended to loop at West Coast Ferry Ter, skipping Clementi West St 2.
		1996	TBC	Amended to ply PIE and Clementi Ave 6, skipping Toh Tuck Ave.
		1999	20 September	Serves new pair of bus stops outside and opposite West Bay Resort Condo along West Coast Rd.
Known as prior to 10 May 2004		2000	18 June	Operations transferred to Trans Island Bus Services.
	Bukit Batok ↺ Kent Ridge	2001	15 April	Shortened to loop at Kent Ridge Ter.
	189Bukit Batok ↺ Kent Ridge 189ABukit Batok → Bt Batok St 23	2009	5 January	189AIntroduced from Bt Batok Int to Bt Batok St 23 (Opp Midview Bldg) during morning peak hours on weekdays.
			1 June	Designated wheelchair-accessible bus service (WAB).
		2011	12 June	189AExtended to operate after the last bus of Service 189 daily.
		2013	TBC	189ALast bus extended to 0100 hrs daily.
	189Bukit Batok ↺ Clementi Ave 1 189ABukit Batok → Bt Batok St 23	2014	23 November	Amended to loop at Clementi Ave 1 with the introduction of Service 201, skipping West Coast Rd and Kent Ridge Ter.
				189Last bus extended to 2315 hrs daily.
(Current)		2016	29 May	Operations transferred to Tower Transit Singapore.
		2019	5 October	189ALast bus extended to 0110 hrs daily.
		2024	28 January	Serves additional bus stop after Clementi Swim Cplx along AYE.

Service 189A

Operator	Route	Year	Date	Service changes
	Bt Batok ↺ Harbour Dr	2001	15 April	Introduced between Bt Batok Int and Harbour Dr (Loop), operating at selected timings only.
		2003	4 May	Discontinued.