The Carberry_highway_collision is the worst of its kind in Manitoba. Of course even a highway with a concrete divider can still have plenty of crashes.
https://en.wikipedia.org/wiki/Municipality_of_North_Cypress_-_Langford
https://www.cbc.ca/news/canada/manitoba/shared-health-update-carberry-mass-casualty-event-1.6879117
https://www.cbc.ca/news/canada/manitoba/crash-carberry-manitoba-1.6877826
In canada, several highway intersections still don't have overpasses and have traffic lights instead. At-grade intersections, especially on the Trans-Canada Highway, should be brought up to proper freeway standards.
https://vancouver.citynews.ca/2023/06/15/manitoba-bus-crash-canada
A divided highway can be a little safer than one that isn't.