It's the last week of 50 km/h speed limit on most residential streets in Calgary

Calgary's new 40 km/h speed limit takes effect next Monday, May 31 for residential side streets.

Tony Churchill, a senior traffic engineer with the City of Calgary, says of the nearly 9,000 collisions a year on the side streets of Calgary, about 550 of them involve injuries or death.

City council approved lowering the speed limit from 50 to 40 km/h in February, in a bid to improve road safety in neighbourhoods.

"At the end of the day, it's just about making our communities objectively safer in terms of having fewer collisions, but also making them more comfortable for people," Churchill told the Calgary Eyeopener.

"This is really about neighborhood roadways. These are roads in neighbourhoods where people live."

Churchill said council has been talking about reducing speed limits to make residential communities safer for decades by targeting residential streets, while leaving busier collector roads at the current 50 km/h speed limit.

"In communities where there's houses there, the collector road is the slightly busier road within the neighborhood, that has other services like strip malls, schools, quite often there are bus routes, those types of things, those are just the roads that have a little bit more traffic on them in neighbourhoods," he said.

Work crews have installed about 5,000 new speed limit signs over the past few months.

Churchill said the signs are mostly 50 km/h signs, posted on collector roads where the speed limit is not changing. 

The new signs come with a cost of roughly $2 million, and Churchill said the the project should come in under budget.

"In our estimate, we had included a lot of concrete bases — which require excavation — for the poles for new signs, but we were able to put a lot of signs on existing infrastructure, just extending existing aluminum poles or putting the vast majority of our speed limit signs on existing streetlights," Churchill said.

The city has estimated the reduction will save at least $8.1 million a year in costs associated with everything from fatalities to property damage, as well as reducing noise levels.

Churchill says with the switch, Calgary will be catching up to numerous other Canadian municipalities that have already gone to a lower speed limit, such as Edmonton, Toronto and Hamilton.

The city's website has a map showing where the lower speed limits will go into effect. 

With files from the Calgary Eyeopener.