King's Highway 420, commonly referred to as Highway 420, is a 400-series highway in the Canadian province of Ontario that connects the Queen Elizabeth Way (QEW) with downtown Niagara Falls. It continues east as a limited-access expressway named Niagara Regional Road 420 to connect with the Rainbow Bridge international crossing between Canada and the United States over the Niagara River; this was part of Highway 420 until 1998. West of the QEW, the freeway ends at an at-grade intersection with Montrose Road (Niagara Regional Road 98). The highway has a speed limit of , making it the only 400-series highway to have a speed limit less than for its entirety. Originally constructed as a divided four-lane road with two roundabouts, the route of Highway 420 formed part of the QEW in 1940 initially as the southeastern terminus, but after the QEW extension from Niagara Falls to Fort Erie opened in 1941, this bypassed highway became a spur route designated as the Rainbow Bridge Approach. It was assigned a unique route number as part of the 400-series after being upgraded into a freeway in 1972, including construction of a large interchange with the QEW. In 1998, the section of Highway 420 east of Stanley Avenue was transferred to the responsibility of the Regional Municipality of Niagara and redesignated as Regional Road 420. Route description At , Highway 420 is the shortest 400-series highway, travelling through Niagara Falls from Montrose Road to Stanley Avenue, on the outskirts of the city's tourist district. East of Stanley Avenue (Regional Road 102) the highway becomes Niagara Regional Road 420 and is known as Falls Avenue and Newman Hill on approach to the Rainbow Bridge. This portion was designated a part of Highway 420 until 2000, when it was transferred to the City of Niagara Falls and the Regional Municipality of Niagara, although the Ministry of Transportation of Ontario (MTO) still assists with the maintenance of it under a Connecting Link agreement. East of Drummond Road, Highway 420 features stylized light fixtures with the letters "ER", which stand for Elizabeth Regina and are a tribute to Queen Elizabeth The Queen Mother. Highway 420 begins in the west at a signalized intersection with Montrose Road (Regional Road 98), beyond which it continues as Watson Street through the residential neighbourhood of Greens Corners to Beaverdams Road (Regional Road 53). East of Montrose Road, the highway is a four