due to logistical issues, I have to postpone the razor-blade thread to next week
in the meantime, let's talk about these little guys
🧵
in the meantime, let's talk about these little guys
🧵
this is an Interstate Highway sign
it's part of a system of standardized signage used on Interstate Highways in the United States
it's part of a system of standardized signage used on Interstate Highways in the United States
you might just call them "freeways" but the network of roads is officially the Dwight D. Eisenhower National System of Interstate and Defense Highways, named for the president who signed the Federal-Aid Highway Act of 1956
the system has nearly 50,000 miles of highways criss-crossing the Fruited Plain
Interstates are all controlled-access roads, meaning they use on- and off-ramps and do not cross other roads at grade
the biggest one in the world is about 300 yards from my front door
the biggest one in the world is about 300 yards from my front door
Interstates are designed and built to standards promulgated by the Federal Highway Administration, an agency of the U.S. Department of Transportation
that department is led by Secretary Pete Buttigieg, shown here absolutely devouring that hog
that department is led by Secretary Pete Buttigieg, shown here absolutely devouring that hog
with a standardized network of roads, you need a standardized system of signage
that's set forth in the Federal Highway Administration's Manual on Uniform Traffic Control Devices for Streets and Highways, or MUTCD
mutcd.fhwa.dot.gov/kno_11th_Editi…
that's set forth in the Federal Highway Administration's Manual on Uniform Traffic Control Devices for Streets and Highways, or MUTCD
mutcd.fhwa.dot.gov/kno_11th_Editi…
this manual, along with the Standard Highway Signs publication, goes into excruciating detail on sizes, dimensions, colors, typefaces, you name it
for example:
speed limit signs in kilometers per hour, like you might see near the Canuckistani border, must have the limit circled
for example:
speed limit signs in kilometers per hour, like you might see near the Canuckistani border, must have the limit circled
so let's talk about each kind of sign
the Interstate shield is used to mark Interstates
states may optionally include the name of the state
the Interstate shield is used to mark Interstates
states may optionally include the name of the state
the number represents the number of the highway
east-west Interstates have even numbers, with the lowest numbers in the south of the country and rising as you go north
when complete, I-2 will run from Peñitas, Texas to Harlingen, Texas
I-96 runs from Norton Shores, Mich. to Detroit
east-west Interstates have even numbers, with the lowest numbers in the south of the country and rising as you go north
when complete, I-2 will run from Peñitas, Texas to Harlingen, Texas
I-96 runs from Norton Shores, Mich. to Detroit
north-south Interstates have odd numbers, with the lowest numbers in the west and rising as you go east
I-5 runs from the Mexican border at San Ysidro, Calif. to the Canuckistani border at Blaine, Wash.
I-99 runs from Bedford, Pa. to Painted Post, N.Y.
I-5 runs from the Mexican border at San Ysidro, Calif. to the Canuckistani border at Blaine, Wash.
I-99 runs from Bedford, Pa. to Painted Post, N.Y.
three-digit numbers represent either a spur or a loop around a city
spurs have odd first digits, loops have even first digits
the next two represent the parent highway
for example, this one is a loop around Houston, bisected by I-10
avoid at all costs
spurs have odd first digits, loops have even first digits
the next two represent the parent highway
for example, this one is a loop around Houston, bisected by I-10
avoid at all costs
Alaska's Interstates are kinda weird
they're just numbered A-1 through A-4
and nobody calls them by their numbers
and they're not interstate
and they're not controlled-access
just two-lane roads
that view though
they're just numbered A-1 through A-4
and nobody calls them by their numbers
and they're not interstate
and they're not controlled-access
just two-lane roads
that view though
Hawaii's are - you guessed it
H-1 through H-3, plus H-201, which loops around Honolulu
H-1 through H-3, plus H-201, which loops around Honolulu
the MUTCD specifies different colors for different classes of signs
red means a full stop is required
red means a full stop is required
orange is for temporary warning signs related to construction
yellow is for warnings about the condition or design of the upcoming segment of highway
green is for guide signs, exits and mile markers
in Colorado and Idaho, they replaced the mile marker 420 signs with 419.9 because stoners kept stealing them
i'm sure they steal those too
in Colorado and Idaho, they replaced the mile marker 420 signs with 419.9 because stoners kept stealing them
i'm sure they steal those too
black and white are used for regulatory signs
most of these are speed limits, but there are others
most of these are speed limits, but there are others
blue is used to inform drivers of upcoming services or the lack thereof
brown is for cultural, historic and recreation sites
apparently pink is used for temporary incidents
I have never seen one of these
I have never seen one of these
the typefaces are specified by Federal fiat, in Standard Alphabets for Traffic Control Devices
right down to the kerning and leading
mutcd.fhwa.dot.gov/SHSe/Alphabets…
right down to the kerning and leading
mutcd.fhwa.dot.gov/SHSe/Alphabets…
so what are the signs made of?
they can be plastic or wood, but they're almost always aluminum
they're faced with a material called "sheeting," which has little prisms or spherical glass beads in it
this allows them to be retroreflective
they can be plastic or wood, but they're almost always aluminum
they're faced with a material called "sheeting," which has little prisms or spherical glass beads in it
this allows them to be retroreflective
they reflect light back in the direction it came from
which is the front of your car
which is pretty close to your eyes
which is the front of your car
which is pretty close to your eyes
hey they're just like retroreflective pavement markers
what luck!
what luck!
https://x.com/mattbramanti/status/1762355383731998818
the Federal Highway Administration has detailed specifications for the required coefficient of retroreflectivity of various materials in various colors
highways.dot.gov/safety/local-r…
highways.dot.gov/safety/local-r…
the poles can be wood or steel (tube, U-channel or I-beam)
regardless of the material, they have to behave well when struck by a vehicle
they can be:
-breakaway (the pole breaks off and flies over the car when you hit it)
-yielding (it bends flat and you run over it)
-shielded (blocked by a guardrail or other barrier)
regardless of the material, they have to behave well when struck by a vehicle
they can be:
-breakaway (the pole breaks off and flies over the car when you hit it)
-yielding (it bends flat and you run over it)
-shielded (blocked by a guardrail or other barrier)
here's a breakaway pole
those bolts are narrowed at the flange to weaken them
just like fire hydrants!
those bolts are narrowed at the flange to weaken them
just like fire hydrants!
https://x.com/mattbramanti/status/1817015504126501155
the Federal Highway Administration even recommends anti-theft measures
to include hammering the end of the bolt holding the sign to the pole
this offends me
highways.dot.gov/safety/local-r…
to include hammering the end of the bolt holding the sign to the pole
this offends me
highways.dot.gov/safety/local-r…
but I have to say my favorite part of the Manual on Uniform Traffic Devices is this
the errata
dozens and dozens of acknowledged errors
please fix, Mayor Petemutcd.fhwa.dot.gov/htm/11th/error…
the errata
dozens and dozens of acknowledged errors
please fix, Mayor Petemutcd.fhwa.dot.gov/htm/11th/error…
so that's the signage
now a little history on the Interstate Highway System
in 1919, the U.S. Army Motor Transport Corps sent a convoy from Washington, D.C. to Oakland, Calif. to test the Army's cross-country mobility
the convoy of 81 vehicles took 62 days to drive the 3,251 miles
now a little history on the Interstate Highway System
in 1919, the U.S. Army Motor Transport Corps sent a convoy from Washington, D.C. to Oakland, Calif. to test the Army's cross-country mobility
the convoy of 81 vehicles took 62 days to drive the 3,251 miles
that's 52 miles a day
a day
virtually nothing between Nevada and California was paved
a day
virtually nothing between Nevada and California was paved
the convoy included cars, motorcycles, heavy and light trucks, 39 officers and 258 enlisted men
among the officers was this fella
28-year old brevet Lt. Col. Dwight D. Eisenhower
among the officers was this fella
28-year old brevet Lt. Col. Dwight D. Eisenhower
Ike would later contrast those dusty roads with the Reichsautobahnen
the Federal-Aid Highway Act of 1956 would allow states and localities to site Interstates, with Uncle Sam kicking in up to 90 percent of the funding
the Federal-Aid Highway Act of 1956 would allow states and localities to site Interstates, with Uncle Sam kicking in up to 90 percent of the funding
there's an urban legend that the Act required one in five miles of Interstate to be straight and level, so that it could be used as a military airstrip in case of war
this is not true
there were pilot programs in the 40s to identify lengths of highway that could be so used
this is not true
there were pilot programs in the 40s to identify lengths of highway that could be so used
the Australian government has identified segments of outback roads for emergency use by the Royal Flying Doctor Service
during the Cold War, Sweden had a dispersal plan to spread its air force across the country in case of war
this included building mini-airbases all over the country, many of which used highways as runways
this included building mini-airbases all over the country, many of which used highways as runways
anyway, i'm rambling at this point
that's Interstate signage
i hope you enjoyed it; if I missed anything or got anything wrong, let me know
previous deep-dive threads are here:
next one will be on razor blades, next Friday
that's Interstate signage
i hope you enjoyed it; if I missed anything or got anything wrong, let me know
previous deep-dive threads are here:
next one will be on razor blades, next Friday
https://x.com/mattbramanti/status/1824638504602595458
dammit
that should read "virtually nothing between Illinois and California was paved"
I regret the error
that should read "virtually nothing between Illinois and California was paved"
I regret the error
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