|This article relies on references to primary sources. (February 2008)|
Hokusō Line 7500 series EMU
|Locale||Tokyo and Chiba Prefecture|
|Opened||March 9, 1979|
|Owner||Hokusō Railway (between Keisei-Takasago and Komuro)
Chiba New Town Railway (between Komuro and Inba-Nihon-Idai)
|Line length||32.3 km (20.1 mi)|
|Track gauge||1,435 mm (4 ft 8 1⁄2 in)|
|Electrification||1,500 V DC overhead catenary|
|Operating speed||105 km/h (65 mph)|
The Hokusō Line (北総線 Hokusō-sen ) is a commuter rail line operated by the Hokusō Railway in Japan. It runs between Keisei-Takasago Station in Katsushika, Tokyo and Inba-Nihon-Idai Station in Inzai, Chiba.
The rail line had been opened in March 1979 on a temporary basis. As other tracks were connected, it changed name to "Hokusō Kōdan Line" in April 1987. Over 17 years later, the railway properties of the HDC corporation transferred to Chiba New Town Railway (千葉ニュータウン鉄道 Chiba Nyūtaun Tetsudō ), on July 1, 2004, and the whole line was renamed as the Hokusō Line.
Basic data 
- Operator: Hokusō Railway
- Length: 32.3 kilometres (20.1 mi)
- Hokusō Railway between Keisei-Takasago and Komuro 19.8 km Category-1
- Chiba New Town Railway between Komuro and Inba-Nihon-Idai 11.5 km Category-3 (Hokusō Category-2)
- Gauge: 1,435 mm (4 ft 8 1⁄2 in) standard gauge
- Stations: 15
- Track: Double
- Power: 1,500 V DC
- Block system: Automatic (ATS Type 1)
- Maximum speed: 105 kilometres per hour (65 mph), upgrading to 130 kilometres per hour (81 mph) for Narita Rapid.
Western section 
The line was planned as a railway access to Chiba New Town. Initially planned by a committee of the then Ministry of Transport, the route was numbered "Line 1", as the northern extension of Tokyo Metropolitan Bureau of Transportation (Toei) Line 1 (present Asakusa Line) to Komuro area of Chiba New Town. In 1979 the first phase section between Kita-Hatsutomi and Komuro opened. The through-operation via Shin-Keisei Line to Matsudo began, on a temporary basis until the second phase section could connect the town directly to the Keisei and Asakusa Line network.
The second phase line to Keisei-Takasago on Keisei Main Line opened in 1991, and through-operation began. In the following year, Shin-Keisei included Shin-Kamagaya Station as a transfer station, and abandoned the temporary route.
Eastern section 
The section east of Komuro was initially the eastern end of a once-planned Chiba Prefectural Railway (千葉県営鉄道 Chiba Ken'ei Tetsudō ) (II, apart from the first which opened the Tōbu Noda Line and the Kururi Line) as an extension of Line 10 (Shinjuku Line). The line was to be built from Motoyawata via Komuro to parallel to the line above, then to terminate at present Inba-Nihon-Idai. The first section between Komuro and Chiba New Town Chūō was opened in 1984, and the operations were commissioned to the present Hokusō Railway.
- March 9, 1979: Hokusō Line (first phase) of Hokusō Development Railway (北総開発鉄道 Hokusō Kaihatsu Tetsudō ) Kita-Hatsutomi – Komuro. Through-operation via Shin-Keisei Line to Matsudo on temporary basis.
- March 19, 1984: Chiba New Town Line (千葉ニュータウン線 Chiba Nyūtaun sen ) of Housing and Urban Development Corporation (住宅・都市整備公団 Jūtaku Toshi Seibi Kōdan ) (HUDC onwards) Komuro – Chiba New Town Chūō
- April 1, 1987: On the section of Komuro – Chiba New Town Chūō, Hokusō Development Railway became the Category-2 Railway Business operator, while HUDC became Category-3 Railway Business. On the commencement of the Railway Business Act (鉄道事業法 Tetsudō Jigyō Hō ), Act No. 92 of 1986) for the privatization of the Japan National Railways Simultaneously, the entire stretch was renamed to Hokusō Kōdan Line (北総・公団線, lit. Hokusō and the Corporation Line)
- March 31, 1991: Hokusō Line (phase 2) Keisei-Takasago – Shin-Kamagaya. Through-operations by four parties (Hokusō, Keisei Electric Railway, Tokyo Metropolitan Bureau of Transportation (Toei), Keihin Electric Express Railway (Keikyū) began.
- July 4, 1992: Shin-Keisei opened Shin-Kamagaya Station. Through-operation to Shin-Keisei terminated. The section of Kita-Hatsutomi – Shin-Kamagaya was abandoned.
- April 1, 1995: Chiba New Town Chūō – Inzai-Makinohara, as Hokusō Cat-2, HUDC Cat-3
- 1999: HUDC reorganized to the Urban Development Corporation (都市基盤整備公団 Toshi Kiban Seibi Kōdan ) (HDC onwards), continued state of Cat-3 of the line.
- July 22, 2000: Inzai-Makinohara – Inba-Nihon-Idai, as Hokusō Cat-2, HDC Cat-3. Present stretch completed.
- July 1, 2004: Railway properties of HDC transferred to Chiba New Town Railway (千葉ニュータウン鉄道 Chiba Nyūtaun Tetsudō ), and the whole line was renamed as the Hokusō Line.
Most trains are all-station "Local" services, but some limited-stop "Rapid" express trains have operated in morning and evening hours.
- Local (普通Futsū) (L)
- Stops at all stations, all day. Through to Keisei Electric Railway (Keisei) Main Line and Oshiage Line, Tokyo Metropolitan Bureau of Transportation (Toei) Asakusa Line, Keihin Electric Express Railway (Keikyū) Main, Airport, Kurihama lines.
- Express (急行 Kyūkō ) (Ex)
- Evening, down from Keisei line.
- Limited Express (特急 Tokkyū ) (LE)
- Morning, up toward Keisei line.
|KS10||Keisei-Takasago||京成高砂||S||S||S||Keisei Main Line, Keisei Kanamachi Line||Katsushika||Tokyo|
Tōbu Noda Line
|HS12||Chiba New Town Chūō||千葉ニュータウン中央||S||S||S||Keisei Narita Airport Line||Inzai|
|HS14||Inba-Nihon-Idai||印旛日本医大||S||S||S||Keisei Narita Airport Line (Through service to Narita Airport on Skyliner service)|
Rolling stock 
Hokusō Railway 
- 7260 series (since 2006, converted from Keisei 3300 series EMUs)
- 7300 series (since 1991)
- 7500 series (since 2006)
Chiba New Town Railway 
- 9000 series (since 1984)
- 9100 series (since 1994, also known as "C-Flyer")
- 9200 series (since March 2013)
Keisei Electric Railway 
- 3000 series (since 2003)
- 3050 series (since 2010)
- 3400 series (since 1993)
- 3500 series (refurbished sets only)
- 3700 series (since 1991)
Toei Subway 
Hokusō Railway 
- 7000 series (from 1979 until 2007)
- 7050 series (rebadged Keisei 3150 series cars leased from Keisei)
- 7150 series (from 1991 until 1998, converted from former Keikyu 1000 series EMUs)
- 7250 series (from 2003 until 2006, converted from former Keisei 3150 series EMUs)
Shin-Keisei Electric Railway 
- 800 series (also leased to Hokusō Railway)
- 8800 series
- 8900 series
- Keisei 200 series
Keisei Electric Railway 
- 3050 series (original) (until 1995)
- 3100 series (until 1998)
- 3150 series
- 3200 series (until 2007)
- 3300 series (unrefurbished sets)
- 3500 series (unrefurbished sets)
- 3600 series
Toei Subway 
- 5000 series
- 5200 series
- 1000 series (until 2010)
Extension to Narita Airport 
After the abandonment of the planned Narita Shinkansen, routes of rapid transit to Narita Airport had long been discussed. For a utilization of partially completed tracks of the Shinkansen, JR East and Keisei lines to Narita Airport were realized. A much faster line had long been needed, and for that purpose the first priority was the Keisei – Hokusō route. In 2001, a new Cat-3 entity, Narita Rapid Rail Access (成田高速鉄道アクセス Narita Kōsoku Tetsudō Access ) commenced building of a new line connecting Inba-Nihon-Idai to the junction to Narita Airport Rapid Railway (成田空港高速鉄道 Narita Kūkō Kōsoku Tetsudō ) which is a Cat-3 company of existing access railways, the tracks of the formerly planned Narita Shinkansen. The express trains are operated by Keisei as a Cat-2 operator with maximum speed at 160 kilometres per hour (99 mph), the fastest in Japanese private railway together with Hokuetsu Express, which enables a 34-minute journey from Nippori to Narita Airport. The line opened in July 2010.
- Official website (Japanese)