The speed limit is to increase to 110 km/h from 100 km/h on most twinned sections of the highway.
Manitoba Premier Greg Selinger first promised the change last fall.
He says it will allow a better flow of traffic.
Selinger says since 2007 the province has spent $242 million to upgrade the Trans-Canada Highway.
The government says other improvements to the highway east of Portage la Prairie that were started last year are to be completed this summer.