Federal Route 255
Sultanah Bahiyah Highway
Route information
Length	13.84 km (8.60 mi)
Major junctions
Northeast end	Alor Setar (North) Interchange
Major intersections	FT 256 FT 175 Jalan Langgar FT 1 Darul Aman Highway K137 Jalan Suka Menanti/Jalan Gangsa FT 7 Federal Route 7 FT 78 Kuala Kedah Highway FT 1 Sultan Abdul Halim Highway FT 1 Federal Route 1 North–South Expressway Northern Route / AH2
Southeast end	Alor Setar (South) Interchange
Location
Country	Malaysia
Primary destinations	Bukit Kayu Hitam, Kangar, Kuala Kedah, Penang, Ipoh, Kuala Lumpur
Highway system
Highways in Malaysia Expressways Federal State

The Sultanah Bahiyah Highway^[1] (Malay: Lebuhraya Sultanah Bahiyah), Federal Route 255 (formerly Alor Setar Bypass and Jalan Sultanah, both Kedah State Route K139) is a major highway bypass in Alor Star, Kedah, Malaysia.^[2] It was named after the late Sultanah Bahiyah, a first consort of Sultan Abdul Halim of Kedah. The Kilometre Zero is located at Alor Setar North.

In November 2003, after a first consort of Sultan Abdul Halim of Kedah, Sultanah Bahiyah, died on 26 August 2003, the Kedah state government renamed the highway Sultanah Bahiyah Highway in her honour.

In 2013, the highway was gazetted as Federal Route 255.

At most sections, the Federal Route 255 was built under the JKR R5 road standard, with a speed limit of 90 km/h.

The entire route is located in Kota Setar District, Kedah.

Legend:

• I/C - Interchange, I/S - Intersection, RSA - Rest and service area, OBR - Overhead bridge restaurant, R/R - Restaurant and rest plaza, L/B - Layby, V/P - Vista point, TN - tunnel, T/P - Toll plaza, BR - Bridge

Km	Exit	Name	Destinations	Notes
0.0	25501 178	Alor Setar (North)–NSE I/C	North–South Expressway Northern Route / FT 1 / AH2 – Hat Yai (Thailand), Bukit Kayu Hitam, Jitra, Pendang, Penang, Kuala Lumpur	Trumpet interchange
	T/P	Alor Setar (North) Toll Plaza	Touch 'n Go SmartTAG MyRFID MyRFID SmartTAG Touch 'n Go
1.3	L/B	Alor Setar (North) Toll Plaza	Alor Setar (North) Toll Plaza – TnG TAG Customer Service Centre
1.4		PLUS PLUS Expressways section maintenances office PROPEL PROPEL section maintenances office
1.6	25502	Jalan Langgar I/S	FT 256 Jalan Langgar – Langgar, Pokok Sena, Jitra, Kepala Batas, Sultan Abdul Halim Airport, Kota Sarang Semut, Gurun, Sungai Petani	Junctions
		Taman Uda I/S	Lorong Bayu – Taman Uda, Taman Bayu	T-Junction
		Jalan Alor Semadom I/S	K399 Jalan Alor Semadom – Jalan Tun Razak, Taman Seri Murni, Taman PKNK, Taman Kenari, Taman Kenari Biru, Taman Mutiara, Taman Rakyat, Stadium Darul Aman	T-junction
4.1	25506	Darul Aman Highway I/S	FT 1 Darul Aman Highway – Anak Bukit, Kepala Batas, Jitra, Sultan Abdul Halim Airport, City Centre	T-junctions
	BR	Sungai Anak Bukit bridge
		Kampung Pumpong
	25507	Jalan Suka Menanti/Jalan Gangsa I/S	K137 Jalan Suka Menanti/Jalan Gangsa – Jitra, Jerlun, Gunung Keriang, Alor Setar city centre, Mergong	T-Junctions
		Taman Wira Mergong
		Taman Wira I/S	Taman Wira Mergong, Taman Seri Belida	T-Junction
		Taman Shahab
		Taman Senangin
		Taman Mergong Indah
		Taman Selayang
7.0	25512	Alor Setar North I/S	FT 7 Malaysia Federal Route 7 – Padang Besar, Kangar, Kuala Perlis, Jerlun, Kuala Sungai, Ayer Hitam (Kedah), Alor Setar City Centre, Mergong	Junctions
	BR	Sungai Kedah bridge
		Taman Mergong Jaya
		Bandar Baru Mergong I/S	Persiaran Bandar Baru Mergong – Bandar Baru Mergong	T-Junction
		Taman Rakyat
		Mergong Industrial Park I/S	Mergong Industrial Park, Taman Impian, Taman Gemilang Jaya, Taman Seri Impian, Taman Seri Indah, Bandar Baru Mergong	T-Junction
		Taman Rakyat I/S	Taman Rakyat Mergong, Kampung Jaya	T-Junction
		Taman Samudera I/S	Jaln Kilang Tebu – Taman Sri Bandar, Taman Kantan, Taman Sinaran, Taman Anggerik, Taman Pelangi, Taman Sri Abadi, Taman Sri Merpati, Taman Merpati, Taman Ria, Peremba, Seberang Perak, Tongkang Yard, Taman Bahagia, Taman Bunga Raya	Junction
		Taman Berjaya I/S	Jalan Teratai- Taman Berjaya, Taman Desa, Taman Sultan Badlishah, Taman Malid, Taman Bahagia, Taman Anggerik, Taman Kantan	Junction
12.0	25517	Kuala Kedah Highway	FT 78 Kuala Kedah Highway – Kuala Kedah, Yan, Tanjung Dawai, Semeling, Merbok, Sungai Petani, Kuala Kedah jetty ( Ferry to Langkawi Island), Alor Setar City Centre, Simpang Kuala, Alor Mengkudu, Tanah Merah (Kedah)	Junctions
		Desa Seraya
		Tandop Industrial Park junction	Tandop Industrial Park, Taman Desa Seraya, Taman Desa Kiara	T-Junction
		Wan Mat Saman Aqueduct Bridge
14.0	25519	Alor Setar South I/S	FT 1 Sultan Abdul Halim Highway – Alor Setar City Centre, Simpang Kuala, Alor Mengkudu, Kota Sarang Semut, Gurun, Sungai Petani	Junctions
14.6		Lotus Hypermarket Alor Setar
		Stargate I/S	FT 1 Malaysia Federal Route 1 – Sungai Petani, Gurun, Tandop, Simpang Empat (Kedah), Tokai, Kota Sarang Semut, Stargate	T-Junction
		Alor Setar Welcome Arch
15.3	L/B	Alor Setar (South) Toll Plaza	Alor Setar (South) Toll Plaza – TnG TAG Customer Service Centre
	T/P	Alor Setar (South) Toll Plaza	Touch 'n Go SmartTAG MyRFID MyRFID SmartTAG Touch 'n Go
15.6	BR	Railway crossing bridge
15.7	25521 177	Alor Setar (South)–NSE I/C	North–South Expressway Northern Route / FT 1 / AH2 – Hat Yai (Thailand), Bukit Kayu Hitam, Jitra, Pendang, Penang, Kuala Lumpur	Trumpet interchange