But what Rigamarole suggested isn’t really a Michigan left, since a Michigan left isn’t a true U turn across an undivided road. Michigan lefts involve medians/boulevards. On a boulevard, you have in practice two, parallel, one way streets, and you cross the boulevard from one one-way street to the other one-way street.
Michigan lefts are truly a miracle of traffic engineering, and I’m still undecided if they win against modern roundabouts or not (they’re really just that perfect. The advantage of a modern roundabout is that you don’t require a boulevard, I suppose.
Oh, so what’s the advantage of the Michigan left? The majority of the traffic (those not making turns) moves through in less time. Instead of four light cycles (NB/SB, turns, EB/WB, turns), there are only two light cycles (NB/SB than EB/WB). The vast majority of the straight-through traffic isn’t held up for a left-turn signal that may or may not be over- or under-utilized. For those that need to execute a left turn, it also provides an advantage in heavy traffic. Instead of waiting three, four, five, or more cycles for the left-turn signal, you’re all but guaranteed to get through in two or fewer changes.
Here’s an example: In this option, to turn left in order to go EB, we’ll go NB, turn around, and turn right to go EB. It works like this: NB/SB has green, and so you go through. While NB/SB is green, the U-turn is red (if traffic’s clear, you can go on the red). As soon as the major road EB/WB is green, the U gets green. You proceed back to the intersection, which may still be red. As soon as EB/WB traffic is clear, or NB/SB gets the green, you make your right turn towards EB. Depending on timing and traffic, you can actually make this left turn without encountering a red light or even stopping your vehicle!
When I travel to other parts of the country (or even parts of Michigan that we didn’t install Michigan turns at), it’s always frustrating watching the inefficiency and waste of the protected left turn signals.
