Dedicated Left Turn Lanes
Dedicated Left Turn Lanes
(OP)
This might seem like a bizarre question. When one analyze/compare volumes of a single left dedicated turn lane with dual left turn lanes, do you
consider a friction factor that is caused when people take the turn at the same time?
Initially you would think that increasing one lane to two lanes would double capacity. However, is this really true is the average speed is that the turn is made is less b/c there is a shy factor with the adjacent car making the
turn simultaneously? Or is this not significant?
consider a friction factor that is caused when people take the turn at the same time?
Initially you would think that increasing one lane to two lanes would double capacity. However, is this really true is the average speed is that the turn is made is less b/c there is a shy factor with the adjacent car making the
turn simultaneously? Or is this not significant?





RE: Dedicated Left Turn Lanes
The lanes don't really double your left turn capacity, because the lane utilization isn't balanced, but, they allow more traffic to get through during the same time.
RE: Dedicated Left Turn Lanes
I do not see any shy distance or speed reduction from adjacent turning vehicles. I do note that many prefer the outside lane rather than the median lane when alone at the stop bar.
Doubling the capacity would be wonderful but the extra travel distance for the outside lane does reduce the number that can clear during any cycle. We estimate a 67% increase in capacity.