Interstate 90 goes east out of Seattle, eventually terminating in Boston. The freeway was originally built in 1940 from Rainier Avenue to Issaquah. It passes through the Eastside's largest city, Bellevue, and skirts the north side of Factoria Mall in Bellevue, where it interchanges with the north–south Interstate 405. Then the freeway continues east and passes through Issaquah, Snoqualmie, and North Bend before climbing into the Cascade Mountains. The freeway originally consisted of four lanes, and crossed the Lacey V. Murrow Floating Bridge. In the early 1950s, an interchange was built at Rainier Avenue and the highway extended 1 mile closer to Seattle's city centre along "Corwin Place". In the early 1960s, traffic congestion forced the Department of Highways to institute a tidal flow system, in which three lanes, controlled by overhead signals went into Seattle in the morning, and toward Bellevue in the afternoon. In 1968, improvements to the east of Mercer Island were made; the highway was widened to up to 6 lanes in each direction and the interchange with I-405 was upgraded from a cloverleaf to a fully directional interchange. Litigation kept the 7-mile section between Bellevue and Interstate 5 from being upgraded until the 1980s, at which time a new bridge from the Eastside to Mercer Island was built and the dangerous "bulge" was removed from the Lacey V. Murrow Floating Bridge. In 1990, the renovations/widening of the freeway were completed, including the new Homer M. Hadley Memorial Bridge over Lake Washington to carry westbound traffic and the HOV/reversible lanes, or express lanes, from Bellevue to Seattle, with general-purpose traffic allowed to use the reversible lanes in between Mercer Island and Seattle. The express lanes carry westbound traffic in the morning and eastbound traffic in the afternoon. Further improvements are now being made to put HOV lanes in both outer roadways to ready the center roadway for Sound Transit's Link light rail.