2nd Airport Expressway
Route information
Length	11.5 km (7.1 mi)
Existed	2008–present
Major junctions
From	Yaojiayuan Road in Chaoyang District, Beijing
To	Terminal 3 at Beijing Capital International Airport
Location
Country	China
Province	Beijing
Highway system
Transport in China
← Beijing S50 → Beijing S66

The 2nd Airport Expressway (Chinese: 首都机场第二高速公路), officially numbered S51, is a toll expressway that connects eastern Beijing with Terminal 3 of Beijing Capital International Airport. It opened on February 29, 2008, just prior to the 2008 Beijing Olympics. It runs for 11.5 km from Yaojiayuan Road in Chaoyang District to Terminal 3. It was built to serve the new Terminal 3, and to reduce pressure of Airport Expressway, which has been heavily congested.

v t e Roads and expressways of Beijing
Projected roads shown in italics
Ring roads	2nd 3rd 4th 5th (S50) 6th (G4501) Capital Area Loop (G95) National Highway 112
Chang'an Avenue (list of sections)	Shijingshan Road Fuxing Road Fuxingmen Outer Street Fuxingmen Inner Street West Chang'an Avenue East Chang'an Avenue Jianguomen Inner Street Jianguomen Outer Street Jianguo Road (side) / Jingtong Expressway (main)
Ping'an Avenue (list of sections)	Linglong Road Chegongzhuang West Road Chegongzhuang Street Ping'anli West Street Di'anmen West Street Di'anmen East Street Zhangzizhong Road Dongsi Shi Tiao Gongren Stadium North Road Agricultural Museum South Road Chaoyang Park South Road Yaojiayuan Road Shigezhuang Road (side) / 2nd Airport Expressway (main)
Guang'an Avenue (list of sections)	Guang'an Road (side) / G4 Beijing - Hong Kong/Macau Expressway (main) Guang'anmen Outer Street Guang'anmen Inner Street Luomashi Street Zhushikou West Street Zhushikou East Street Guangqumen Inner Street Guangqumen Outer Street Guangqu Road
Central Axis (list of sections)	Beichen Road Gulou Outer Street Old Gulou Street Di'anmen Outer Street Di'anmen Inner Street (Split into west and east part near Jingshan, Palace Museum and Tian'anmen Square) Qianmen Street Tianqiao South Street Yongdingmen Inner Street Yongdingmen Outer Street Nanyuan Road (Nanyuan Airport to be demolished) Nanzhongzhou Road (Provincial Highway S228)
Qiansanmen Avenue (list of sections)	Lianshi West Road Lianshi East Road Lianhuachi West Road Lianhuachi East Road Xuanwumen West Street Xuanwumen East Street Qianmen West Street Qianmen East Street Chongwenmen West Street Chongwenmen East Street Tonghui River North Road (side) / Tonghui River North Express (main)
Xuanwumen Avenue (list of sections)	Zhixin East Road Huayuan East Road Beitaipingzhuang Road Xinjiekou Outer Street Xinjiekou North Street Xinjiekou South Street Xisi North Street Xisi South Street Xidan North Street Xuanwumen Inner Street Xuanwumen Outer Street Caishikou Street Kaiyang Road Majiabao West Road Huaifang West Road
Chongwenmen Avenue (list of sections)	Beiyuan Road Huixin West Street Yinghuayuan West Street Hepingli West Street Yonghegong Street Dongsi North Street Dongsi South Street Dongdan North Street Chongwenmen Inner Street Chongwenmen Outer Street Tiantan East Road Puhuangyu Road Liuxiang Road Dexian Road G3 Third Beijing-Tianjin Corridor
Other	Fengti South Road - Lize Road G109 - Fushi Road - Fucheng Road - Fuchengmen Outer Street - Fuchengmen Inner Street Chaoyangmen Inner Street - Chaoyangmen Outer Street - Chaoyang Road - Tongzhou - Yanjiao Expressway Xishiku Street - Deshengmen Inner Street - Deshengmen Outer Street - G6 Andingmen Inner Street - Andingmen Outer Street - Anding Road - Anli Road - Litang Road Caihuying South Road - G45 (To Kaifeng/Guangzhou) Xizhimen Outer Road - Xueyuan Road - Xueqing Road Zizhuyuan Road - Xingshikou Road Wanquanhe Road - Yongfeng Road Huilongguan-Shangdi Bicycle Lane (cycleway)
Expressways	National Expressways G1 Beijing-Shenyang G0121 Beijing-Qinhuangdao G2 Beijing-Tianjin-Tanggu G3 Third Beijing-Tianjin Corridor G4 Beijing-Shijiazhuang G5 Second Beijing-Shijianzhuang Corridor G6 Badaling G7 Beijing-Baotou G45 Beijing-Kaifeng/Beijing-Chengde G4501 6th Ring Road G95 Capital Area Loop Sections of National Highways G101 Beijing-Miyun (partially upgraded) G102 Tongzhou-Yanjiao G103 Beijing-Tongzhou G106 Beijing-Kaifeng G109 Beijing-Lanzhou (not yet upgraded) Regional expressways in Beijing-Tianjin-Hebei area S3201 Beijing-Pinggu-Jizhou S3301 Second Beijing-Tianjin Corridor S3501 Expressway for 2nd Airport S3701 Beijing-Yuxian S3801 Beijing-Chongli S3300 Northern 2nd Airport Beijing-Xiong'an Local expressways S11 Beijing-Chengde S12 Airport S15 Second Beijing-Tianjin Corridor S26 Changping-Pinggu S28 Northern Airport S32 Beijing-Pinggu S37 Expressway for 2nd Airport S41 Miyun-Caiyu S46 Beijing-Tongzhou - Tongzhou-Yanjiao Connection S50 5th Ring Road S51 Airport 2nd S66 Beijing-Kunming Connection S76 Yanjiao-Caiyu S80/G95 Miyun-Zhuozhou
National Highways	G101 Beijing-Liaoning G102 Beijing-Harbin-(Fuyuan) G103 Beijing-Tanggu(Binhai New Area) G104 Beijing-Fuzhou-(Pingtan) G105 Beijing-Zhuhai-(Macau) G106 Beijing-Guangzhou G107 Beijing-Shenzhen-(Hong Kong) G108 Beijing-Kunming G109 Beijing-Lhasa G110 Beijing-Yinchuan-(Qingtongxia) G111 Beijing-Jiagedaqi-(Mohe) G112 Beijing Ring G230 Tonghua-Wuhan G234 Xinglong-Yangjiang G335 Chengde-Tacheng G509 Tongzhou-Jingtang Port