This might be surprising but understandable:

The number of vehicles coming in and out of downtown Vancouver in 2010 is about the same as it was in 1965.

But this?

Calgary traffic flow: Some downtown streets less busy than in 1964.

From Calgary’s Metro:

Major entryways into the Beltline like 4th Street and 14th Street SW, for example, saw less traffic in 2012 than they did in 1964, when the city’s population was a quarter the size.

“It is a little bit surprising,” Ekke Kok, the city’s manager of transportation data, said of the historical vehicle counts he and his predecessors have collected since Grant MacEwan was mayor.

In Vancouver, the biggest difference – in addition to the sheer growth of the downtown population – was the improvement in transit.  Same in Calgary:

(Transit advocate William) Hamilton added that the drop in vehicle traffic on Macleod Trail can be connected to the expansion of the south leg of the C-Train line in the early 2000s.

“If you make mass transit such as the C-Train a viable option for more commuters, then absolutely more people are going to take it, and that’s going to take strain off the road infrastructure,” he said.

And this:

Kok said a number of factors are likely at play in the changing traffic patterns over the decades, including “a conscious decision” made by city planners “not to increase the capacity of some roads” in the downtown area while also constructing a variety of other major thoroughfares.

And this:

The number of people riding Calgary Transit buses increased by 136 per cent between 1995 and 2013, he noted, while car traffic grew by just 1.2 per cent over the same period, according to the city’s annual “cordon counts” of traffic flowing in and out of the city’s core.

Pedestrian numbers, meanwhile, grew by 102 per cent and bicycle traffic increased by 153 per cent, although they make up a much smaller proportion of the total traffic volume.