Udon Ratthaya Expressway (Thai: ทางพิเศษอุดรรัถยา), also known as the Bang Pa-in–Pak Kret Expressway (Thai: ทางด่วนสายบางปะอิน–ปากเกร็ด), is an expressway in City of Thailand, located in Nonthaburi, Pathum Thani and Phra Nakhon Si Ayutthaya states. The expressway is a controlled-access toll road. It connected from Si Rat Expressway (Sector C) at Chaeng Wattana Interchange. Its length is 32 kilometers (114.286 kilo-studs)