The fatalities included highway worker Ashley Richards, who was struck while working as a flag person in a construction zone.
The government has announced more signage in work zones so drivers know when they have to slow down.
The usual orange signs with black worker figures on them will clearly state when workers are actually present.
A black-and-white speed sign will immediately follow to remind motorists to drive no faster than 60 kilometres an hour.
The government has also raised fines for people caught speeding in construction zones.
The fines have increased to a minimum of $210 from $140. They go up for each kilometre over the limit a driver is speeding.
"We need these new signing measures, plus education and enforcement, to make a real change in driving behaviours in the work zone," Highways Minister Don McMorris said in a release Monday.