Declines in Interprovincial traffic on bridges

This is a guest post by John Verbaas, continuing on the theme of declining traffic counts even while we build more roads:

“Here’s  one that is dear to my heart.  The information is from a graph taken from the Dillon Consulting Study in 2009-2010 done for studying the impact of reducing King Edward from 6 lanes to 4 lanes.
It shows the 10 yr  trend analysis of daytime traffic volumes on all of the Ottawa River Crossing bridges.  The traffic is flat to declining on all of these bridges except the westernmost one (Champlain).   Amazingly somehow the NCC decided in their study not to pursue expansion of crossings in the west…only in the east…even though that is where the declining traffic trend is the greatest !!! (Macdonald-Cartier bridge)….but alas, that is another story….
Back to the main point… the chart shows both peak hour traffic and the twelve hour trend. One could argue that the 12 hour trend analysis in the chart is more interesting than the 2.5 hr one….because obviously in the 2.5 hour peak the bridges are running pretty close to capacity and it would be hard to demonstrate rising traffic demand in the peak.  Instead additional demand could only be accommodated by spreading the traffic outside of the peak.  So if we look beyond the peak period, to this wider 12 hour measure …. it shows declining traffic.  Hmmm….
No doubt traffic levels are rising in the city, especially beyond the core…but certainly within the core,  more and more evidence is coming to light that traffic levels appear to have peaked.