Over the past 12 years, Lt. Megge has increased the speed
limit on nearly 400 of Michigan’s roadways. … Lt.
Megge advocates for raising speed limits because he believes it makes
roads safer.
Traffic Engineering 101
Every
year, traffic engineers review the speed limit on thousands of
stretches of road and highway. Most are reviewed by a member of the
state’s Department of Transportation, often along with a member of the
state police, as is the case in Michigan. In each case, the “survey
team” has a clear approach: they want to set the speed limit so that 15%
of drivers exceed it and 85% of drivers drive at or below the speed
limit.
This
“nationally recognized method”
of setting the speed limit as the 85th percentile speed is essentially
traffic engineering 101. It’s also a bit perplexing to those unfamiliar
with the concept. Shouldn’t everyone drive at or below the speed limit?
And if a driver’s speed is dictated by the speed limit, how can you
decide whether or not to change that limit based on the speed of
traffic?
The answer lies in realizing that the speed
limit really is just a number on a sign, and it has very little
influence on how fast people drive. “Over the years, I’ve done many
follow up studies after we raise or lower a speed limit,” Megge tells
us. “Almost every time, the 85th percentile speed doesn’t change, or if
it does, it’s by about 2 or 3 mph.”
… Years of observing traffic has shown engineers that as long as a cop car
is not in sight, most people simply drive at whatever speed they like.
Luckily, there is some logic to the speed people choose
other than the need for speed. The speed drivers choose is not based on
laws or street signs, but the weather, number of intersections, presence
of pedestrians and curves, and all the other information that factors
into the principle, as Lt. Megge puts it, that “no one I know who gets
into their car wants to crash.”
So if drivers disregard speed limits, why bother trying to set the “right” speed limit at all?
One
reason is that a minority of drivers do follow the speed limit. “I’ve
found that about 10% of drivers truly identify the speed limit sign and
drive at or near that limit,” says Megge. Since these are the slowest
share of drivers, they don’t affect the 85th percentile speed. But they
do impact the average speed -- by about 2 or 3 mph when a speed limit is
changed, in Lt. Megge’s experience -- and, more importantly, the
variance in driving speeds.
This is important because, as noted in a U.S. Department of Transportation report,
“the potential for being involved in an accident is highest when
traveling at speed much lower or much higher than the majority of
motorists.” If every car sets its cruise control at the same speed, the
odds of a fender bender happening is low. But when some cars drive 55
mph and others drive 85 mph, the odds of cars colliding increases
dramatically. This is why getting slow drivers to stick to the right lane
is so important to roadway safety; we generally focus on joyriders’
ability to cause accidents -- and rightly so -- but a car driving under
the speed limit in the left (passing) lane of a highway is almost as
dangerous.
It seems absurd that over half of
drivers technically break the law at all times. It’s also perplexing
that speed limit policy so consistently ignore traffic engineering 101.
So why do people like Lt. Megge need to spend their time trying to raise
speed limits?
How Saudi Arabia Got Us All Driving 55 MPH
"When
I drive that slow, you know it's hard to steer. And I can't get my car
out of second gear. What used to take two hours now takes all day. Huh,
it took me 16 hours to get to L.A."
~ Sammy Hagar’s hit song “I Can’t Drive 55”
In
1973, the Egyptian military crossed the Suez Canal in a surprise attack
on Israel. It was the start of the 1973 Arab-Israeli War, and also low
speed limits in the United States.
When the United
States began resupplying Israel with arms, the Organization of Arab
Petroleum Exporting Countries announced an embargo against the United
States and several other countries. Combined with other supply
constraints, it led to a quadrupling of gas prices, shortages of
gasoline, and long lines at the pump.
In an effort to reduce America’s need
for gas, President Nixon issued an executive order mandating a 55 miles
per hour speed limit on American highways, which Congress made law the
following year. States are officially in charge of setting their own
speed limits, but national leaders (semi) successfully cajoled states by
tying compliance to federal highway funds. Since driving at high speeds
is less efficient, the policy is estimated to have saved
167,000 barrels of oil per day, or around 1% of American motor oil consumption.
Even
as the effects of the energy crisis drew down in the 1970s, the new
federal speed limit remained. But rather than insist on the limit in
order to reduce gasoline consumption, members of Congress maintained the
policy because they believed it led to safer highways. This is shown by
a debate over a measure passed in 1987, which allowed select states to
raise the limit on certain roads to 65 mph. The
New York Times reported
that “Critics immediately warned that there would be a surge in highway
fatalities.” The dissenting chairman of the Public Works and
Transportation Committee called it “irresponsible, life-threatening
legislation.''
Congress abolished the national federal speed limit in
1995. Many states increased their speed limits before they could even
post new signs, but many speed limits remained low. Twenty years of a 55
miles per hour speed limit created a low baseline that drags down speed
limits today.
Why Speed Limits Are Low
If you peruse the websites of state’s departments of transportation, you’ll often find a very
technocratic explanation
of the 85th percentile principle. Speed limits are consistently lower
than the 85th percentile speed across the country, however, because
there are many limitations on following the principle. Florida’s
Department of Transportation, for example,
extolls
the 85th percentile principle, yet the state legislature sets maximum
limits for each type of roadway. Locally, officials can come under
pressure from parents and other safety-conscious groups to lower speed
limits.
Consistently, the 85th percentile loses out to the
perception that faster roads are less safe, so speed limits should be
low. It’s a misconception, Lt. Megge says, that he faces often in his
work. When he proposes raising a speed limit, the initial reaction is
always “Oh my god! You can’t do that. People are already going too
fast.” People think raising the limit 10 mph will lead people to drive
10 mph faster, when really changing the limit has almost no impact on
the speed of traffic.
The same lack of understanding
motivates public health pushes for lower speed limits that influence
legislation. The World Health Organization, for example,
advocates
low speed limits to prevent road fatalities, and cites studies showing
that accidents and fatalities increase with traffic speed.
“When you
look at it from a pure physics standpoint,” Megge says, “and ask would
you rather hit a bridge abutment at 10 mph or 40 mph, you can’t argue
with that. But when I look at correcting a speed limit, I am not
advocating driving faster, and that’s the hard part to get over.”
If someone could wave a wand and get
every American to drive below 60 mph, roads would be safer. But since
law enforcement can’t keep over 50% of Americans from speeding, putting a
low number on a sign can’t make roads safer. Fortunately, American
roadways are safer than ever, with highway fatalities at
historic lows. Roads can be dangerous, but the perception of roads getting increasingly dangerous is a false one.
… The other reason speed limits may remain low, which John
Bowman, Communications Director of the National Motorists Association
strongly insists on, is that cities and police departments use traffic
citations as a revenue generating tool. As Bowman says, when speed
limits are artificially low, it’s easier to give out citations and pull
in fine revenue.
Due to concern about such “speed
traps,” Missouri passed a law in the 1990s that capped the amount of a
town’s revenue that could come from traffic tickets. In 2010, auditors
discovered that Randolph, Missouri, generated
75% to 83% of its budget
from traffic tickets. The tiny town of around 50 residents, which is
located near several casinos, employed two full-time and eight part-time
police officers, turning it into a speed trap poster child.
Figuring
out how common the tactics used by Randolph’s police department are
around the country is difficult, as is tying it to a conscious decision
to keep speed limits low. Each town or city makes its own decisions,
which makes it difficult to know how comprehensively speeding tickets
are used as a revenue generator. Further, it is very easy for police
departments to defend pushing officers to issue more tickets as a goal
intended to further roadway safety -- as the LAPD did when
found in violation of a state law banning traffic ticket quotas last year.
In
our conversation, Lt. Megge stated that he believes speed traps to be a
“big problem” and counter to police officers real role of altering
dangerous behavior. In a
Detroit Newsarticle
about a number of towns ignoring state law by not reviewing the speed
limits on stretches of their roads, Megge said that he believes the
communities did so in order to avoid revising speed limits upwards. This
allows them to keep
collecting ticket revenue on “artificially low”
speed limits.
… “I don’t want to lie to people,” Lt. Megge tells us. It
may make parents feel better if the speed limit on their street is 25
mph instead of 35 mph, but that sign won’t make people drive any slower.
Megge prefers speed limits that both allow people to drive at a safe
speed legally, and that realistically reflect traffic speeds. People
shouldn’t have a false sense of safety around roads, he says.
If
people and politicians do want to reduce road speeds to improve safety,
or make cities more pedestrian friendly, Megge says “there are a lot of
other things you can do from an engineering standpoint.” Cities can
reduce the number of lanes, change the parking situation, create wider
bike paths, and so on. It’s more expensive, but unlike changing the
number on a sign, it’s effective.
Raising speed limits up to the speed of
traffic can seem like surrendering to fast, unsafe driving. But it would
actually accomplish the opposite. If advocates like Megge are right,
following the 85th percentile rule would make roads safer, and it would
also mean taking speed limits seriously.
In its 1992 report, the U.S. Department of Transportation
cautioned,
“Arbitrary, unrealistic and nonuniform speed limits have created a
socially acceptable disregard for speed limits.” Lt. Megge has worked on
roads with a compliance rate of nearly zero percent, and a common
complaint among those given traffic citations is that they were speeding
no more than anyone else.
With higher speed limits, Megge says, police
officers could focus their resources on what really matters: drunk
drivers, people who don’t wear seat belts, drivers who run red lights,
and, most importantly, the smaller number of drivers who actually speed
at an unreasonable rate.
It seems counterintuitive, but it’s a formula Americans should love: Raise speed limits, make roads safer.
Sir Roger Moore's
fellow James Bond actors. as well as other celebrities, join in an outpouring to pay
homage after the actor's death.
