Quote:
Originally Posted by Carboy15
|
Good discussion Carboy. He raises true points about platooning.
Here's my problem with Barbell or Dogbone interchanges: They create a similar "weaving" issue as cloverleafs do, creating backlogs. See red arrows
On a freeway, the goal of an overpass is to expedite LEFT traffic ENTERING and EXITING the freeway. Lefts are most frequent.
That's why SPUI's are so brilliant. In mornings, traffic is predominantly turning left, from both sides, to ENTER the freeway. In residential areas. So the SPUI left light can stay almost permanently green giving free flow to BOTH SIDES. Very few cars are going STRAIGHT over top the freeway in mot cases. Few are exiting the freeway either. So left greens can stay long.
In the afternoon, the reverse happens (in residential areas as people return from work). The left lights allows traffic to EXIT the freeway freely, from both sides, without traffic ever crossing. And since left is the predominant direction, the most cars achieve freer flow.
Note: Diverging Diamonds create the same crossing issue as barbells, and regular diamonds; left turn traffic has to cross itself on the highest frequency pathway (lefts). That's why SPUI's are absolutely brilliant. It's basically a diverging diamond, but condensed with only 1 light. Solving all the same problems, only simpler, more efficiently, with less lights on the straight, and
no crossing traffic. #TeamSPUI.