Originally Posted by
The Human Car
In the city we are getting a lot of resistance to road diets because key traffic engineers call the center lane a subside lane and not to mention an over emphases on capacity over smooth (safer) traffic flow (i.e. We need that extra lane for one mile for increased capacity even though it causes a lot of accidents as people try and jump the cue.)
Personally I have no faith in traffic studies that try and predict the end result of a change as there is a very complex list of behaviors and results (What's the goal? To get more cars through on a short light cycle, increase travel speed, reduce accidents, accommodate all users?) I would love to see more trial of designs and compare actual before and after numbers.
IIRC one of the key arguments in favor of 4-3 road diets is that road capacity is typically not affected substantially, since the turning vehicles are moved "out of the way," allowing through traffic to proceed. There are a bunch of safety enhancements too, although I will note that some more recent studies have shown a not insignificant number of head-on crashes in the center turn lane, so there is some movement toward not having the center turn lane extend too far. IMHO the goal ought to be always to make the street good for ALL people, be they cyclists, motorists, freight drivers, pedestrians, and so on.