The intersection of Errol and Indian Roads is expected to be closed from now until about Labour Day.
Sarnia's Construction Manager Robert Williams said intersection improvements are underway.
"Permanent concrete bump-outs that are going to reduce the width of Indian Road to a single lane in each direction, plus turning lanes, [are planned]" said Williams. "That's going to narrow Indian Road and allow for some future bike lanes and in the long run there will be traffic lights coming later in the year."
Williams expects crews will be onsite until the end of August.
"The whole project has been put together to happen throughout the summer. We have a great deal of school buses that use that intersection so we are trying to complete it before Labour Day, before school starts."
Williams said the intersection was closed to through traffic completely on Wednesday and turnarounds are being constructed Thursday over the centre medians on Indian Road for local residents to use.
"Indian Road residents will access their properties by doing U-turns on either side of the intersection. So, if you were to live on Indian Road on the north side of Errol Road, you would access your property southbound on Indian Road and then make a U-turn at the intersection."
Williams said underground infrastructure will be placed during the closure for future traffic lights.
"So, it should be pretty busy there for the next three weeks, to a month, and then the second phase of that project also includes the resurfacing of Errol Road to the east, which is between Indian Road and Murphy Road."
While Sarnia council's vote last December in favour of installing traffic lights was unanimous, its decision on the bump-outs was split and narrowly passed in a 5-4 recorded vote.