12-16-2018, 12:14 PM
(12-16-2018, 11:21 AM)panamaniac Wrote: Why would the four lane through street configuration lead to more collisions? Westmount/Ottawa and Westmount/Victoria both have left turn lanes and both see more collisions than Westmount/Glasgow, although I assume they also see higher traffic volumes.
Needed turn lanes are missing. If one person wants to turn left, the entire left lane is blocked. The people behind them then try (understandably) to move into the right lane. Meanwhile, the right lane can also get blocked if somebody turning right needs to wait for a pedestrian. Net result: the actual capacity of dedicated through lanes is zero.
As far as I’m concerned the selection of the current configuration constitutes professional malpractice.
A more reasonable configuration would be one through lane in each direction, with right- and left-turn lanes. This gives the road a total width of 4 lanes at the intersection and 2 elsewhere. I think most of our 4-lane roads could benefit from this treatment, certainly including Union, Belmont, and Queen’s Blvd. If the 2-lane parts between intersections are done with a median, you get easy intermediate pedestrian crossing for free. This configuration also balance out the capacity more appropriately — instead of unused capacity between major intersections and jammed-up major intersections, you get more fully-used narrow roads combined with intersections that flow smoothly but aren’t of excessive size.
In short, I am highly unimpressed with our traffic “engineers”.