One of the concerns with the Green Line currently being debated in Calgary city council is that Centre Street is a busy street that can’t afford to lose lanes for LRT. Here’s the daily number of users on the major entrance routes into the downtown; the Centre Street upper deck isn’t busier than other routes; several of the other routes carry more traffic.
The busiest routes, the 4th and 5th flyovers, as well as 9 Ave W, Macleod Tr and 1 St SE are one-way roads, mostly of four lanes in one direction. (The 4th Ave Flyover is only 2 lanes, and 9 Ave W is 5 lanes as it enters the CBD.)
The four-lane Centre Street Bridge doesn’t carry that much more traffic than the two lane Reconciliation Bridge or 9 Ave E bridges. But this isn’t the whole story.
Let’s add another piece of data:
This barely changes the picture, but if you squint you can see a few green bits representing buses – the Centre Street bridge has the most of them, which is interesting.
People not vehicles
But it doesn’t matter how many vehicles use a road; the point of a road is to allow people to get places. So it’s people that matter, not the number of vehicles. Once you realize that, the perspective changes entirely:
The Centre Street Bridge upper deck is the busiest route into downtown Calgary, once you consider all users of the facility. Almost half of the users are in the tiny handful of transit vehicles, while the cars that use 99% of the road space to carry barely half the people. And I don’t want to miss the 4% of users who are active mode users – cyclists and pedestrians. It seems pretty fair to me to expand the ability of the bridge to carry transit, given the high demand already shown. If transit can attract 42% of the users with the buses stuck in traffic, what could a real BRT system accomplish?
The clearest takeaway is this — the most efficient way to expand the ability of people to get into the downtown is in making more room for transit vehicles. Even the improved BRT now being discussed for Centre Street would enable more frequent and faster trips, and would increase the capacity of Centre Street substantially.
And since we’re looking at all the modes, a number of other routes are important as well:
The road accesses to downtown are less busy than the (2 lane only) LRT accesses to the downtown.
A Green Line would make the Centre Street Bridge by far the highest capacity route into downtown; the roadway could carry 15-20K users like the two-lane Reconciliation or 9 Ave E bridges, while 60K riders are forecast to use the LRT. (That is a future volume estimate, although it’s not unreasonable since the existing LRT legs are mostly carrying 40-50K daily.) At 80,000 users a day, Centre Street would have almost double the capacity of any existing facility.
Methodology
The above figures are based on the 2017-2019 Calgary CBD Cordon Count program; the three years are averaged to smooth out noise from the one-day count. The totals include both inbound and outbound directions, and all counts are of persons, not of vehicles – except the second figure. I converted transit riders to buses and auto occupants to cars (which I believe includes trucks and other road vehicles) using the average occupancy rates from the 2018 cordon count summary.
Photo is public domain by Bernard Spragg NZ on Flickr.
Mean Median Mode Choice 