10 Things You Might Not Know About the U.S. Interstate System

istock
istock

Inspired by the network of high-speed roads he saw in Germany during World War II, Dwight D. Eisenhower championed the passing of the Federal-Aid Highway Act of 1956. The law funded the first 41,000 miles of paved glory that made up the early U.S. interstate system, which now boasts 46,876 miles and runs through all 50 states. (Yes, even Alaska and Hawaii.) Prepare for your next cross-country (or cross-town) road trip with the following facts.

1. IT TOOK 17 YEARS TO CREATE AND FUND THE IDEA OF THE INTERSTATE.

Two members of the U.S. Bureau of Public Roads presented a report to Congress in 1939 that detailed the need for a non-tolled road system in the U.S. The Federal Highway Act of 1944 allowed for development of a 40,000 mile National System of Interstate Highways, but it didn’t provide any method of funding, so it went nowhere. It wasn’t until the act of 1956 that funding was finally allocated to its construction.

2. PEOPLE FIRST LOVED, THEN HATED IT. 

When the Interstate Highway Act was passed, most Americans thought it was a good idea. But when construction started and people, especially in urban areas, were displaced and communities cut in half, some started to revolt. In the 1960s, activists stopped construction on highways in New York, Baltimore, Washington, D.C., and New Orleans, which resulted in several urban interstates becoming roads to nowhere.

3. EVERY STATE OWNS ITS PORTION (INCLUDING THE POTHOLES) …

This means the state is responsible for enforcing traffic laws and maintaining the section of highway in its borders. Currently, the “largest pothole in the country” award has been claimed by this section of I-75 outside Detroit. 

4. … EXCEPT FOR ONE (FORMER) BRIDGE.

The Woodrow Wilson Memorial Bridge (I-95/495) that crossed the Potomac River into Washington, D.C. used to be the only part of the interstate system owned by the Federal Highway Administration. But issues over it being too small led to the creation of a new, bigger, taller bridge. As for the old one? It was destroyed, in part by people who won a contest for having “the toughest daily drive.”

5. THE STATES SET THE SPEED LIMITS.

However, in the early 1970s, all 50 states set their speed limits to 55 mph. A clause in the Emergency Highway Energy Conservation Act signed into law by Richard Nixon dictated that if a state did not set its highway speed limit to 55 mph, that state would lose its federal highway funding. 

6. THE SIGNS ARE TRADEMARKED.

The red, white, and blue shields used to designate interstate numbers are trademarked by the American Association of State Highway Officials. The original design for the shield was drawn by senior traffic engineer Richard Oliver of Texas and selected out of 100 entries in a national design competition in 1957. 

7. INTERSTATES AND HIGHWAYS WITH THE SAME NUMBER CANNOT RUN THROUGH THE SAME STATE.

The numbering system used for interstates is intended to be the mirror opposite of the U.S. highway system, so drivers won't be confused about whether to take Highway 70 or Interstate 70. For example, I-10 runs through southern states east-west (as all major even-numbered interstates do; odd-numbered interstates run north-south), while Highway 10 runs through northern states. Because I-50 would run through the same states as Route 50, the number will never be used. 

8. I-99 DOESN'T FOLLOW THIS SYSTEM, BUT THAT'S NOT THE FEDERAL HIGHWAY ADMINISTRATION'S FAULT.

According to the Federal Highway Administration's numbering system, Pennsylvania's former US 220 should have been named something like I-876 or I-280. But Representative Bob Shuster wanted a catchier moniker for it. According to The New York Times, as a child he was fond of the No. 99 streetcar, which he used as his inspiration for the road's tag. 

9. THE INTERSTATE IS PART OF THE U.S.' ATOMIC ATTACK PLAN. 

A major concern during Eisenhower’s presidency was what the country would do in the event of a nuclear attack. One of the justifications for the building of the interstate system was its ability to evacuate citizens of major cities if necessary. 

10. THERE ARE NO DESIGN RULES DICTATING THE SHAPE OF ROADS.

A major myth of the interstate system is that one out of every five miles is straight so an airplane can land. While this has happened, there are no rules or regulations that require such a design. Also, there are no requirements for curves to be designed into a highway to keep drivers awake. However, the Federal Highway Administration does admit that this is a perk of winding roads.

10 Juicy Facts About Leeches

Ian Cook
Ian Cook

Leeches get a bad rap, but they’re actually pretty cool once you get to know them—and we're finding out more about them, even today. Recently, a team led by Anna Phillips, curator of parasitic worms at the Smithsonian National Museum of Natural History, discovered a new species of medicinal leech (pictured above) in a Maryland swamp. We asked parasite expert and curator at the American Museum of Natural History Mark E. Siddall to share some surprising facts about the worms we love to hate. 

1. Not all leeches suck blood.

Hematophagous, or blood-feeding, species are only one type of leech. “The vast majority of species are [hematophagous],” Siddall tells Mental Floss, “but it depends on the environment. In North America, there are probably more freshwater leeches that don’t feed on blood than there are blood-feeders.” And even among the hematophagous species, there are not too many who are after you. “Very few of them are interested in feeding on human blood,” Siddall says. “Certainly they’ll do it, if they’re given the opportunity, but they’re not what they’re spending most of their time feeding on.” 

2. Leeches are everywhere.

Japanese leech on a log
Pieria, Wikimedia Commons // Public Domain

“Every continent on the planet has leeches, with the exception of Antarctica,” Siddall says. “And even then there are marine leeches in Antarctic waters.” Humans have co-existed with leeches for so long, according to Siddall, that just about every language has a word for leech. 

3. Leeches have made a comeback in medicine.

Bloodletting for bloodletting’s sake has fallen out of favor with Western physicians, but that doesn’t mean medicinal leeches are enjoying a cushy retirement. Today, surgeons keep them on hand in the operating room and use them as mini-vacuums to clean up blood. “That is a perfectly sensible use of leeches,” Siddall says. Other uses, though, are less sensible: “The more naturopathic application of leeches in order to get rid of bad blood or to cure, I don’t know, whatever happens to ail you, is complete hooey,” he says. How on Earth would leeches take away bad blood and leave good blood? It’s silly.” 

4. Novelist Amy Tan has her own species of leeches.

Land-based leeches made an appearance in Tan’s 2005 book Saving Fish from Drowning, a fact that instantly put the author in leech researchers’ good graces. “There are not a lot of novels out there with terrestrial leeches in them,” Siddall says. So when he and his colleagues identified a new species of tiny terrestrial leeches, they gave the leech Tan’s name. The author loved it. “I am thrilled to be immortalized as Chtonobdella tanae,” Tan said in a press statement. “I am now planning my trip to Queensland, Australia, where I hope to take leisurely walks through the jungle, accompanied by a dozen or so of my namesake feeding on my ankles.”

5. Leeches can get pretty big.

The giant Amazon leech (Haementeria ghilianii) can grow up to 18 inches and live up to 20 years. And yes, this one’s a blood-feeder. Like all hematophagous species, H. ghilianii sticks its proboscis (which can be up to 6 inches long) into a host, drinks its fill, and falls off. Scientists thought the species was extinct until a zoologist found two specimens in the 1970s, one of whom he named Grandma Moses. We are not making this up.

6. Leeches make good bait.

Many walleye anglers swear by leeches. “A leech on any presentation moves more than other types of live bait," pro fisher Jerry Hein told Fishing League Worldwide. "I grew up fishing them, and I think they're the most effective live bait around no matter where you go." There’s an entire leech industry to provide fishers with their bait. One year, weather conditions kept the leeches from showing up in their typical habitats, which prevented their collection and sale. Speaking to CBS news, one tackle shop owner called the absence of leeches “the worst nightmare in the bait industry.”

7. Leech scientists use themselves as bait.

Siddall and his colleagues collect and study wild leeches. That means hours of trekking through leech territory, looking for specimens. “Whether we’re wandering in water or traipsing through a bamboo forest,” Siddall says, “we are relying on the fact that leeches are attracted to us.” Do the leeches feed on them? “Oh my god, yes. We try to get them before they feed on us … but sometimes, obviously, you can’t help it.”

8. Leech sex is mesmerizing.

Like many worms, leeches are all hermaphroditic. The specifics of mating vary by species, but most twine themselves together and trade sperm packets. (The two leeches in the video above are both named Norbert.)

9. Some leech species make surprisingly caring parents. 

“There’s a whole family of leeches that, when they lay their eggs, will cover them with their own bodies,” Siddall says. “They’ll lay the eggs, cover them with their bodies, and fan the eggs to prevent fungus or bacteria from getting on them, and then when the eggs hatch, they will attach to the parent. They’re not feeding on the parent, just hanging on, and then when the parent leech goes to its next blood meal it’s carrying its offspring to its next blood meal. That’s pretty profound parental care, especially for invertebrates.”

10. You might be the next to discover a new leech species. 

Despite living side-by-side with leeches for thousands of years, we’ve still got a lot to learn about them. Scientists are aware of about 700 different species, but they know there are many more out there. “I’ll tell you what I wish for,” Siddall says. “If you ever get fed on by a leech, rather than tearing off and burning it and throwing it in the trash, maybe observe it and see if you can see any color patterns. Understand that there’s a real possibility that it could be a new species. So watch them, let them finish. They’re not gonna take much blood. And who knows? It could be scientifically useful.”

22 Weird Jobs From 100 Years Ago

Metal Floss via YouTube
Metal Floss via YouTube

Before everyone started working in tech, people actually had their choice of eclectic and strange vocations that put food on their old-timey tables. Discover what lamplighters, lectores, and knocker-uppers did back in the day as Mental Floss editor-in-chief Erin McCarthy runs down 22 Weird Old Jobs from 100 Years Ago.

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