by RIDOT. RIDOT conducted further planning and environmental studies in the 1970s, proposing to construct the four-lane freeway with a dual carriageway and a landscaped median. The freeway would be constructed over a right-of-way, running through mostly undeveloped land in the Blackstone River Valley. RIDOT planned to construct the highway first as a two-lane freeway to be upgraded at a later date. Further environmental studies in the late 1980s altered the plans for the construction of the Woonsocket Industrial Highway; after studies indicated that the freeway, as originally planned, would interfere with the water supply for the city of Woonsocket, RIDOT revised the proposal, removing the large median and reducing the right-of-way. The freeway was instead planned with a right-of-way and concrete barriers to separate the opposing traffic lanes. The plan to open the highway as a two-lane freeway was also abandoned; instead, all four lanes would be constructed at one time. In the 1980s, the planned Route 325 was also renumbered to Route 99. Construction on Route 99 began in 1987. The project, which included the construction of a four-lane bridge over the Providence and Worcester Railroad and the Blackstone River and new collector/distributor roads on Route 146 between I-295 and Route 99, was completed in 1993. Future The proposal to extend the Woonsocket freeway north to I-495 in Bellingham was placed on RIDOT long-range planning studies in 1971, resurrecting the proposal made by the Massachusetts Department of Public Works in the 1960s. Throughout the 1980s, RIDOT planned the alignment or Route 99 to allow for a northern extension of the freeway beyond Route 122. In 1977, however, RIDOT officially abandoned plans for an extension north to Bellingham, Massachusetts and I-495, instead opting for a shorter route that would extend the freeway north to Route 114 (Diamond Hill Road) in northern Woonsocket. The freeway extension remains on RIDOT's long-term plans. In 2009, RIDOT announced that it would begin resurfacing and repaving the collector/distributor roads serving I-295 and Route 99 from Route 146. Resurfacing the most deteriorated portions of the roads began in March 2009, with a complete repaving scheduled for June 2009. Repaving was later rescheduled for August 2009, but has since been postponed until September. Exit list Exits were unnumbered until November 2017, when they were added as part of a project to convert exits in the state to mileage-based exit numbers, a federal highway standard See also