At a fundamental level, there’s nothing wrong with this
unusual sign in Southfield, MI, a large, busy suburb of Detroit with definitive
Edge City characteristics.
Although signs restricting motorists from turning during certain hours are hardly commonplace, they certainly aren’t unheard of. Obviously, a succession of cars waiting to make a left turn at a busy intersection can create a logjam, deteriorating the Level of Service of any busy arterial, especially during peak travel times. But look at the hours listed on this particular sign.
Although signs restricting motorists from turning during certain hours are hardly commonplace, they certainly aren’t unheard of. Obviously, a succession of cars waiting to make a left turn at a busy intersection can create a logjam, deteriorating the Level of Service of any busy arterial, especially during peak travel times. But look at the hours listed on this particular sign.
Contrary to our expectations, this isn’t a morning
restriction. Left turns are off
limits here from 6:00a all the way until midnight—a whopping 18 hours. Only in the middle of the night (or
early morning), from 12:01a to 5:59a, are vehicles permitted to turn on red.
It probably makes sense: the traffic volume here on
Telegraph Road, just south of W. Twelve Mile Road, is so intense that cars seeking
to turn left probably should have to wait, at least through most of the day. But how likely is it that the human eye
and brain will interpret this correctly the first time around, even when
stopped at the light? After all,
both the beginning and ending restriction times are AM. Most signs advertising use restrictions
only regulate for brief intervals; not three-quarters of the day. Even if a
driver stops here for quite some time, the brain is likely to require time to
process the fact that this restriction completely encompasses the PM hours. And
for those who pass by quickly, then plunge ahead, will they necessarily
interpret the information on this sign accurately? This sign’s unconventional regulation could make it an easy locus
for law enforcement to “catch” motorists in a moving violation. (“But officer,
I thought the sign said…”)
Truth is, this restriction is nothing more than a refinement
of a Michigan left, a fairly common traffic management practice throughout
urban areas in the Wolverine State—but pretty rare just about everywhere
else. This tactic, in which a
motorist makes a right and then a carefully controlled U-turn (often regulated
by stop lights as in the Southfield example above), no doubt reduces chances of
gridlock induced by a left-turn lane, albeit by diverting vehicles across a
more convoluted path. Michigan’s
famously broad thoroughfares, coupled with generous medians, make the Michigan
left superlative at mitigating against the hazard of motorists demurringly
seeking a left turn across a broad intersection. But for the unfamiliar (i.e., the non-Michiganders) the
approach confuses and annoys, because it seems so counter-intuitive. And a road sign with bizarre restrictions
only amplifies this confusion.
In MDOT’s defense, the Michigan left is catching on: Indiana installed one at a busy intersection a few years ago (at the border of Indianapolis and the suburb Fishers),
and southwestern DOTs have begun adopting them. Meanwhile, my former home of New Orleans is perhaps even
more enamored with wide medians than Detroit (though they call them “neutral
grounds” down there), and the city has long embraced a variant on Michigan, in
that motorists usually must make a U-turn at a later point just beyond the intersection,
rather than an immediate left turn at the convergence of the two streets. But the approach involves much more
elaborate signage with the Michigan left in metro Detroit, akin to this graphic.
Will the creeping dissemination of the Michigan left across
other parts of the country eventually make the “6am to 12am” time frame easier
to interpret? Probably not, unless
signage featuring this interval becomes commonplace. And why should it?
Wouldn’t it have been more straightforward simply to say “left turns
allowed – 12am to 6am only”? Or to
depict the interval through military time? But would American civilians ever catch on to the 24-hour
approach, common throughout most of the world? Yeah, that’s about as likely as switching to the metric
system—or surrendering our sovereignty to France. Which pretty much amount to the same thing.