The Secret Genius of Modern Life episode 17 - Motorway
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00:00Take one.
00:05Shall we?
00:06Take a minute.
00:08Look around you.
00:11You probably never think about it,
00:13but we are living in a time of incredible ingenuity.
00:17Our lives are filled with fiendishly clever bits of tech
00:20that basically make the modern world tick.
00:24The problem is, we're now so used to these devices
00:29that we have forgotten to remember how clever they are.
00:33I don't have an answer for that.
00:35I'm Professor Hannah Frye,
00:38your hammer-wielding, tech-curious tour guide
00:45to the secret genius of everyday objects.
00:48There is one law of physics that you need to know.
00:50In each episode...
00:54I will take one seemingly ordinary item...
00:59immediately smoking.
01:02And I'll look at it in, frankly...
01:04Yeah!
01:05...obscene detail.
01:07Two googly eyes.
01:09It has 180-degree view.
01:12Meet the people who helped make it.
01:16This is the very first air fryer.
01:18And follow the twisty, turny journey
01:21through the history of its invention.
01:23If you overshoot the turning point,
01:25don't try to do this.
01:27It's wobbly, Johnny.
01:29Yeah, it's just wind.
01:33Buckle up, folks.
01:34This time, it's the motorway.
01:38OK, I know that motorways get a bit of a bad road.
01:41They're boring.
01:42They're frustrating.
01:44But if you put aside the road range...
01:46What's he doing in that lane?
01:47Do you know what I mean?
01:49...roadworks...
01:51...and roadside rescues.
01:54You have to admit that they have also made our lives
01:56so much easier.
01:59They are the backbone of the country.
02:01A way to get from A to B as fast as possible.
02:04And without them...
02:05I mean, the whole country would just ride to a halt.
02:09Love them or hate them...
02:11Without them, we'd probably be lost.
02:14So how did some wild swimming in the 1950s...
02:19It's gone.
02:21OK, I'm in.
02:23..a Formula One legend...
02:25I'm off the ground completely.
02:27Probably doing 180 mile an hour.
02:29And there's no barrier.
02:31And a 1960s road sign revolution.
02:35The signs that existed, they were absolutely chaotic.
02:39They just wouldn't have worked.
02:41Give us the modern motorway.
02:44You know how people really hate it?
02:45When people sit in the middle lane of the motorway.
02:49Yeah. Guilty.
03:01The best way to see our motorways in action...
03:04...is from the air.
03:06We're going to look at motorways from above, they said.
03:09Great. I said, from a helicopter?
03:11No.
03:12From a drone.
03:16Andrew Marr got a helicopter.
03:21Given the eco-impact of our traffic-laden motorways...
03:25...maybe I can do without a chopper.
03:26From up here, you can see just how much we rely on these high-speed roads.
03:34Have a look here.
03:37Can you see how the traffic's starting to build up?
03:41And if you look at the volume of traffic and trucks and caravans...
03:46I mean, everything running along this road.
03:49All of the trucks carrying all these goods.
03:50From the almost 200 billion tonnes of goods they carry each year...
03:55...to the four million journeys we make on them every day.
04:00This is not just a road. This is the artery of Britain.
04:08We're going to pull apart the motorway and look at everything...
04:12...from crash barriers to cat's eyes.
04:14But we're starting with the bit that can make your daily commute pure pleasure...
04:21...or total Carmageddon.
04:24It's the road.
04:25There are 2,300 miles of this stuff.
04:36Layers of tarmac, gravel and great history...
04:40...that have helped shape our motorway system.
04:43And the people who built it.
04:45Including this one, the M25.
04:47It's quite an Irish history, the M25.
04:52A lot of the tarmac was laid by Irish workers, including Bob Geldof.
04:57I think he tries to claim that where the M25 meets the M23 is Geldof's corner.
05:02I'll let you decide if you want to call it that.
05:05Tell you why I don't like Mondays, Bob.
05:08Rush hour on your motorway for a start.
05:10But since Bob's days, our motorways have gone super high-tech...
05:15...to try and ease our road rage.
05:18There is an enormous amount of completely invisible technology...
05:22...that's going on behind the scenes...
05:24...that is essential to keep everybody moving.
05:27Take these innocuous-looking squares.
05:31They're actually induction loops, quietly monitoring traffic levels.
05:35When you drive over one, it disturbs the magnetic field of a copper coil buried below...
05:41...and pings a signal...
05:43...to these guys.
05:45They're holding traffic.
05:47The whole lane.
05:49Wow, they've closed the whole motorway.
05:52They've closed the whole motorway.
05:56Hidden off Junction 6 is the National Highway's control room for the M25.
06:02Our busiest motorway.
06:03These officers use any means necessary to fight the jams.
06:09Like the MI5 of the M25.
06:12It looks like that's going to be cleared fairly soon then.
06:16Running the place today is Jules Thompson.
06:19We do Junction 30, Vans Junction 14 on the M25.
06:26What we call the smiley side, the M25.
06:29The smiley side?
06:30The smiley side.
06:31Is the north the unhacky side?
06:32I couldn't comment.
06:33Sensors and radar systems tell them the volume and flow of traffic.
06:41And CCTV gives them eyes on the road to pinpoint the problem.
06:45It's all part of a system known as MIDAS.
06:50MIDAS is a motorway incident detection automated system.
06:55And rolls off the tongue, doesn't it?
06:56Absolutely.
06:58Yeah, I think I'll stick to the acronym.
07:03Now before you ask, there is one area that Jules and the MIDAS system don't get involved in.
07:08We get information on speed, but not speed camera-y type information.
07:13So you can't tell if people are speeding?
07:14No, no, no, that's police matter.
07:16Does that mean that sometimes you speed on the motorway?
07:18No, never speed on the motorway.
07:19Absolutely not.
07:21What's going on there?
07:22That's our stationary vehicle detection system.
07:24Ooh.
07:25Going off.
07:26There's an RTC in that road work section.
07:28So where the ambulance is side on, there's a car just in front of it in the central res.
07:32Midas has alerted them to a crash that has blocked a lane and slowed traffic to a crawl.
07:42That's quite a big queue now.
07:44How far back is that going?
07:46About one and a half kilometres.
07:47Five minutes in and we're at one and a half kilometres.
07:49It's really astonishing just how quickly this is causing problems.
07:56Jules sends an officer to clear the crash site.
07:58Stopped traffic costs the UK economy tens of millions of pounds a day.
08:04So every minute counts.
08:07Traffic officers on soon.
08:08You see the people out of the vehicle.
08:13Now being cleared, you can see the traffic's moving through in all lanes.
08:17With the car cleared, you'd think that would be problem solved, wouldn't you?
08:21But stalled traffic takes a while to move, so the tailback is still growing.
08:28Midas steps in, lowering the speed limit to 50 for the cars behind that aren't yet caught in the jam.
08:35It's detecting the queue forming, it is setting the signs for us.
08:43I mean, it feels like it shouldn't work, right?
08:46Slow things down to get them through faster.
08:49Well, let's see.
08:50I have a nice model version of a motorway.
08:54The key thing that you need to know about traffic is that it's all about the relationship between speed and density.
09:05Speed, that's how fast the cars are going.
09:07And density is if you took a photograph from above a stretch of motorway, the density would be how many cars would be pictured in that image.
09:17OK, it's early morning before rush hour.
09:23Everyone's travelling at 70 miles an hour.
09:25This is like ideal motorway driving conditions.
09:29Bit of six music, delightful.
09:33Now, when there aren't many cars on the roads, there's lots of space between them and they rarely affect each other.
09:40Density is low, traffic can flow well.
09:43Now I imagine it gets a little bit later on in the morning.
09:48The dreaded rush hour has begun.
09:51There are more and more cars that are joining the motorway.
09:55But there comes a critical point.
09:57When the density of cars is so high that traffic can no longer flow freely.
10:03Too many cars and they can get in each other's way.
10:05All right, mate, calm down.
10:08Slowing up everyone behind them.
10:11This can quickly escalate into a full-blown traffic jam.
10:16By this point, it's game over.
10:22You know, there's not really anything that you can do.
10:25Everybody's just got to wait their turn to get out of it.
10:28But for these vehicles yet to approach, we can stop the jam from spreading to them.
10:35And the way that you can do this is by using those gantries over the motorway.
10:41If you change the speed limit for the cars back there, just knock it back a little bit to 50.
10:49At this slower speed, everyone has a bit more time and space to pass through without getting in the way of cars around them.
10:57Traffic can again flow smoothly.
11:00Counter-intuitively, because you have reduced the speed, you've also increased the flow.
11:08Which means that more cars can get through than before.
11:14The challenge of keeping us all moving began with the mass production of the motor car.
11:27By the early 20th century, the age of the automobile is clogging our roads with cars.
11:33And so, a new kind of road starts to appear.
11:36In Italy, Mussolini builds 500 miles of fascist fast lanes to show off his modern regime.
11:46The Germans follow with the first autobahns, finished just in time to invade Austria.
11:53Not to be outdone, the Yanks build 40,000 miles of high-speed roads they call highways.
12:00A symbol of their love affair with the car and cheap oil.
12:05This is the American dream of freedom on wheels.
12:10And the first UK motorway, well, we get the exotically named Preston Bypass. Lucky us.
12:18But despite the new roads, the jams didn't stop, much to the despair of the authorities.
12:23If only motorists will just take the trouble and drive at the right speed for their particular vehicle.
12:30This is known as Brace's paradox after German mathematician Dietrich Brace.
12:36He theorised that as new lanes opened, human nature being what it was,
12:40more people will choose these faster roads, eventually clogging them up too,
12:45and increasing overall journey times.
12:47Luckily, another mathematician was about to come up with a theory on traffic that was way ahead of its time.
13:00The year is 1955, and a mathematician by the name of James Lighthill is out on one of his regular wild swims.
13:09I don't belong in this environment. This is outside of my natural habitat.
13:18Oh, my God, it's cold! It's cold!
13:22OK, I'm in.
13:25Unlike me, he took pleasure in plunging into cold water.
13:30You might not have heard of him, but he's a bit of a legend in maths world.
13:34Yes, I think that would be going a bit far.
13:39Because he was one of the best people who's ever lived at understanding the equations of how fluids flow.
13:47And he was so good at this, intuitively knowing what fluids would do as they went through bottlenecks or cracks and gullies.
13:54Can you give me an example of a differential equation in words?
13:57Well, quite a good example is the well-known wave equation d2y by dx squared equals one over c squared times d2y by d squared.
14:09Oh, steady on, James. You're getting me all pi r squared.
14:12So one day, he had this brainwave. He was like, maybe we've been thinking about traffic in completely the wrong way.
14:22Because traffic flows like fluids do. And OK, traffic might be made of cars, but fluids are made of particles.
14:28So if they are similar, can you use the equations of fluid flow to predict how traffic will move and maybe stop traffic jams?
14:43That was really obvious that I was standing there, wasn't it?
14:45In the same way, just one pebble can ripple outwards to affect water far away.
14:56Maybe the same thing was happening on our roads.
15:00It became clear that most traffic jams aren't caused by people having crashes or breaking down.
15:06They're caused by really trivial things.
15:08Like a driver breaking or changing lanes, even in the absence of a clear cause like an accident or roadworks.
15:18All of those little things put together, they add up and they ripple outwards exactly like a water wave.
15:28Allow me to demonstrate in real time and not in a wetsuit.
15:32Remember that drone's eye view of the M25 earlier? Let's take another look at it.
15:43OK, do you see this?
15:46So on the traffic that's coming this way, it's slowed right down, almost to a crawl.
15:53And there's no obstruction anywhere. This is just people braking and then people behind them braking and people behind them braking and so on and so on and so on.
16:02It's like this ripple effect that travels backwards through the field of traffic.
16:07And it's like they've actually stopped. They've stopped.
16:10That's extraordinary.
16:13And it's for no reason other than the cumulative effect of human error.
16:18This is a phantom traffic jam.
16:21This is cars that are stopping without there ever being an obstruction.
16:24Light Hill realised that if everyone drove at a constant speed, these phantom jams would disappear and we'd get places quicker.
16:36And so the traffic flow problem was solved, right?
16:40Wrong.
16:41Look out there, you with the ladder.
16:44Those policy makers don't listen to maths, even excellent maths.
16:49And so road building was seen as the fix to the flow problem.
16:53By the 1960s, the UK had entered a motorway building frenzy.
17:06This motorway starts a new era in road travel.
17:11We were tarmacking the countryside faster than you could say braces paradox.
17:17And by the 1970s, the network stretched to over a thousand miles.
17:23By the 1990s, our roads were clogged with more cars than ever.
17:27The motorway is already a victim of its own success because of the problems of severe congestion.
17:36But over in the world of academia, new research was bringing Light Hill's work back into the spotlight.
17:43Chaos theory looked at how trivial actions can have big consequences.
17:48A butterfly flapping its wings in outer Mongolia this month could affect the weather patterns that we experience over Britain next month.
18:02There were clear parallels with Light Hill's work on traffic jams.
18:07And now, advances in supercomputers and early AI meant they could model his theories
18:13and prove that slowing traffic down to keep it flowing worked.
18:18And so, in the mid-1990s, his calculations were woven into a new, intelligent traffic flow system.
18:27Which brings us back to where we started. Midas.
18:31It works. By slowing the traffic down on approach, it just helps to keep it moving
18:36and to avoid getting into that stop-start, stop-start scenario.
18:40Feels like there's a lesson here. Always trust the mathematicians.
18:49Motorways let us travel fast.
18:52But with speed comes danger.
18:57Our next component is the part of the motorway that could save your life in an accident.
19:02It's the crash barrier.
19:03The crash barrier.
19:12This is designed to absorb the impact and energy of the car and keep the occupants safe.
19:17That is Matt Harriman from crash barrier experts Hill & Smith.
19:27Wow. Wow.
19:29I mean, that whole thing's over in about two seconds.
19:31Two seconds.
19:33He spends his time crashing vehicles so you don't have to.
19:40To test the crash barrier used on most motorways.
19:45That hadn't been there.
19:47I mean, that's really serious across three lanes of traffic.
19:50Yes, exactly, yes.
19:51It's all about saving the drivers.
19:54It's called an Armco barrier after the American rolling mill company that invented it.
20:00And it has to withstand everything our motorways can throw at it.
20:05We test a small car, so 900kg, like a mini.
20:09All the way up to kind of coaches and lorries.
20:12So they need to be tough.
20:21So this is basically a big toilet roll of steel.
20:24Totally roll of steel. I love it.
20:26Definitely not something you'd want to wipe your bum with, though.
20:29And then that's what it becomes?
20:30That's what it turns into, yes.
20:31Can I pick it up?
20:32Pick it up if you want, yes.
20:35I mean, it's actually lighter than I was expecting it to be.
20:37Yes, yes.
20:38Given that this has to stop a car.
20:39It's how thin it is, which is extraordinary.
20:42Three millimetres, that's all it is.
20:46The key to getting something this thin to be so strong is its shape.
20:53It starts off, like a piece of paper, has no strength at all.
20:58So if this was like a barrier like this?
20:59Yes.
21:00What would happen if you went into it?
21:01It's just plopping and bend over and break.
21:03Oh, right, OK.
21:04Just tearing it half.
21:06So we put the folds in it and it makes it nice and rigid.
21:11But not so rigid that it stops the vehicle instantly.
21:15Humans don't react well to sudden stops or sudden change of direction.
21:20So it slows them down gradually.
21:22You can really see that.
21:24That sort of takes on the properties of like an elastic band.
21:28Exactly, yes.
21:30Like an unbreakable cushion?
21:31An unbreakable cushion, definitely, yes.
21:36I suddenly feel so much safer.
21:38Good.
21:39It's up to 55 miles an hour.
21:40Maybe going slightly faster.
21:47To find out why that W is the ideal shape, I've sneaked into the back of the factory to try out my own barrier.
21:59First, I need a crash test dummy.
22:01And I have an egg-cellent candidate.
22:06I'm going to draw a face on it just to really get that emotional investment.
22:10Let's call him Egbert.
22:15He's looking a little worried.
22:17And for good reason.
22:18Because I have here Egbert's car.
22:20And a solid wall that he is going to crash into.
22:27This is unforgiving.
22:28There is no flex in this thing at all.
22:30This is going to be a very abrupt stop.
22:34But to allow Egbert to build up some speed, I've got something you don't find too often on motorways.
22:41A big old ramp.
22:47OK, Egbert is belted in and ready.
22:50Go!
22:53OK, now that's quite an impact.
22:58As the car comes down the ramp, it builds up all this momentum.
23:01It has lots of energy.
23:02And then when it hits the wall, it stops dead.
23:05And all that energy has to go somewhere.
23:07Which means that the forces inside the car are very high.
23:11Those forces are felt by the surface of Egbert's shell.
23:16Omelette, anyone?
23:17Now, if this was a real car, the car would be in shatters, right?
23:20The front would be crumpled, it would be an absolute disaster.
23:23But watch what happens when I install my expertly crafted flexible cardboard crash barrier.
23:30It's got a W shape to it.
23:34So let's just pop this in front.
23:36Maybe this time I'm going to do an Egbert that's just slightly more confident.
23:40A little bit more cocky.
23:42Bit of a daredevil.
23:44So now, everything else is the same, right?
23:46The ramp's the same, the egg's the same, the car's the same.
23:48But look at what happens when you let go instead.
23:54Ooh!
23:56How you doing there, little guy?
23:58He's fine!
23:59You can see, though, the barrier ends up being quite dented.
24:03Quite a big old dent there.
24:04And there's a clue in that.
24:06Some of the energy of stopping has dissipated through the crash barrier itself.
24:12The W-shaped barrier is designed to deform when hit by a vehicle.
24:20As it bends and crumples, it absorbs much of the force that would have gone into the car.
24:27By allowing some cushioning on the impact, Egbert has got away scot-free.
24:34The wiggly W barrier is a crucial motorway safety feature.
24:38But how did we get them?
24:45The first crash barriers were simple walls or fences.
24:49Sadly, they tended to make injuries worse.
24:55In 1933, the corrugated Armco barrier arrived.
25:00It proved so good, it quickly became standard across the US.
25:04This test on a W section was at 60 miles per hour,
25:07at an angle of 25 degrees.
25:11But when the M1, the UK's first full motorway, opened in 1959,
25:17they decided to rely on something else for safety.
25:20It will bring immense benefits if drivers use discipline and obey the rules.
25:28Yes, no crash barriers, just some nice, firm rules.
25:31If you overshoot the turning point, don't try to do this.
25:36Unsurprisingly, this did not prevent serious accidents.
25:40And so a solution was urgently needed.
25:43It would come from a speedy Scotsman.
25:45So many of our friends died that something had to be done about it.
25:57That is Formula One legend, Sir Jackie Stewart.
26:00He started racing in 1961 at just 22 years old and quickly found success.
26:09Racing ace, Jackie Stewart.
26:12It was a kind of magic ride, actually.
26:15A big magic ride.
26:16But the world of Formula One was also a death trap, with few safety precautions.
26:27In almost every circuit there were no safety barriers.
26:31As Jackie discovered during a pivotal championship race in 1966.
26:35It was pouring with rain.
26:41Got to the part of the race track that's famous for its speed.
26:46It was a huge river of water.
26:50I got it full blown.
26:54And I dropped off a telegraph pole, I dropped off a woodcutter's hut.
27:00Jackie lay badly injured in his car for almost half an hour.
27:10Finally got me out of the car.
27:12Took me into the barn of a farmhouse.
27:16And I was burning, you know.
27:18So I was coming in and out of consciousness.
27:22It was during his recovery from the accident that Jackie realised things had to change.
27:27He'd had a lucky escape compared to many.
27:31It was a strange world at that time because we were losing friends all of the time.
27:38And the lack of safety precautions were clearly to blame.
27:42I'm off the ground completely there.
27:46Probably doing 180 miles an hour.
27:48And there's no runoff area.
27:50There's no barrier.
27:52That's what we were racing against.
27:53Jackie knew he was one of the few people who might be able to bring about change.
28:03Something had to be done about it.
28:05By which time I had won a couple of world championships or so.
28:09And therefore I had power.
28:13He started to campaign for improved safety and race track barriers.
28:16Even persuading other drivers to boycott a big race.
28:21I closed the Nürburgring ring because I was then chairman of the Grand Prix Drivers Association.
28:27But not everyone was on board.
28:31The changes would cost big money.
28:33And critics thought that safer tracks could detract from the sports excitement.
28:37I mean I got a lot of threats from my life and abuse from the organizers.
28:48But I was also winning.
28:51And that was very difficult for them to forget.
28:55Eventually the sports governing body agreed to install crash barriers at the 1969 Spanish Grand Prix.
29:05Soon after they appeared on all major race circuits.
29:09I'm forever proud that I was able, against incredible odds, to close down some of the biggest race tracks in the world.
29:23Because they wouldn't put their house in order.
29:27And yet the UK's motorways were still barrier free.
29:32With British MPs more keen to debate the benefits of rose bushes as a form of safety barrier.
29:39The big problem is the narrowness of the central reservation.
29:44There isn't really enough width to be able to grow bushes that can form a natural barrier.
29:50But with their success in Formula One, Jackie had brought Armco barriers to prominence.
29:56When you're at the top of an international sport, you're dealing with heads of state.
30:02You're talking sometimes to governments, you're talking to track owners, you're talking to team owners.
30:09Finally, in the early 1970s, Armco barriers were installed on the M1.
30:14And by the 1980s, they were standard on British motorways, ultimately saving thousands of lives.
30:20When I'm no longer here will probably be my participation in changing the level of removing danger from our sport.
30:34Because if Formula One gets put into shape, it's a domino effect to every other.
30:40Today, our motorways are the safest roads we have, carrying over 20% of all traffic, but with only 5% of fatalities.
30:53Driving is a dangerous business, but in the dark, it can be even more treacherous.
31:05Thankfully, there is a clever piece of tech keeping an eye on you and lighting the road ahead.
31:11It's our next component, the cat's eye.
31:24OK, sorry, can you just...
31:26Ah, sorry.
31:28Excuse me.
31:29There are over 12 million cat's eyes, sorry, reflective road studs as they're known in the industry, scattered across our roads.
31:44Despite using only the light from our headlights, they are incredibly effective.
31:49So how do they work?
31:52So if we can just turn the lights off for a second.
31:55Because it doesn't matter what direction you shine the light at.
32:01It shines straight back at you.
32:06Regardless of how you move around.
32:10And that means that when you are hurtling down the motorway,
32:14you will always be able to see these things reflecting back at you.
32:20And when you think about it, there is something quite incredible about that.
32:23This is a design that has no batteries, almost no real moving parts.
32:28And to see how it manages to do that, I think it requires a little bit of cat surgery.
32:35Not you, Moggy, you're OK.
32:40What a scaredy cat.
32:41Cat's eyes are remarkably uncomplicated things.
32:47You've got the heavy base, then you've got this rubber insert.
32:51And inside here are the cat's eyes themselves.
32:55I'm going to just pop one of these out, using some appliance.
33:00There you go.
33:02I think it's time for my trusty hacksaw.
33:12And once you get down to the centre of it, it's almost laughably simple.
33:17This is a glass bead with a reflective surface on the back.
33:21And it is what makes cat's eyes work.
33:24Hold it there.
33:26In case you're wondering, it's also how the eye works in an actual cat.
33:29So at the back of a cat's eye, they have a layer of cells called the tapetum lucidum, which acts like a reflective surface.
33:42And it means that they have much better vision in low light conditions.
33:45But it's also why their eyes glow in the dark.
33:51But it's the angle of reflection that is key here.
33:55Let me show you what I mean with this laser pen and a mirror.
34:00You might imagine that a reflective surface on its own would be enough.
34:04Just pop mirrors into the road surface, it will reflect your headlights backing.
34:08Well, viewer, you'd be wrong.
34:09Watch what happens when I shine the laser into the mirror.
34:13Now, for this, I'm going to have to wear a pair of glasses partly because it protects my eyes from the laser.
34:20But mostly because it makes me look cool.
34:25Now, you can see with this, with this laser, that I'm pointing at the mirror from this direction over here.
34:30This is your headlights. You're kind of sitting up here.
34:32This is where you want the light to be reflected back to.
34:34But instead, it's hitting the mirror and then bouncing off somewhere over in the back.
34:41Where the cats can play with it, I think.
34:49Mirrors reflect light based on the angle it hits them.
34:53Most of the time scattering the light in different directions, which is not ideal on the road.
34:58But the cat's eyes bring a clever solution.
35:04And watch what happens when you add in the glass bead, in this case represented by the beautiful glass orb.
35:11If you place that in front of the mirror and then do the exact same thing, you'll notice something very different.
35:18Oh, yeah. Can you see that?
35:25Look, it's shining right back at me.
35:28This is no longer this bounce that's going off over there in the distance.
35:33It's shining right back onto my hand, the position where the light beam is coming from.
35:37As the laser passes through the glass ball, it bends the light perfectly towards the exact centre of this curved mirror.
35:50And at that point, it can reflect straight back in the direction that it came from, rather than being bounced off in loads of different directions.
35:56And so it doesn't matter what angle you're at, doesn't matter how fast you're going, what lane you're in, you are always going to be able to see these cat's eyes twinkling from the road beneath you.
36:09I mean, that is very cool.
36:14The trusty cat's eye is a simple and brilliant way to light up the road and keep us safe.
36:21But where did they come from?
36:28Early roads had no markings at all.
36:31Until one day in 1911, American road official Edward Hines was out cycling and got stuck behind a leaky milk wagon.
36:43He noticed it leaving a trail of white and had a genius idea.
36:48Why not use paint to mark out the road lanes and maybe stop people smashing into each other?
36:53White road lines kept us on the straight and narrow, but they had one big flaw.
37:04They were pretty tricky to see at night.
37:07It would take a Yorkshireman, a cat and a headlamp to solve that problem.
37:18Let's take a drive to 1930s Booth Town.
37:21Home to road worker Percy Shaw.
37:26It was a great one for enjoying his beer.
37:30And the whole invention occurred because it had to get to the pub and back on a regular basis.
37:39That is Glendashaw, our Percy's great granddaughter.
37:44Percy was an early adopter of the motor car and drove to the pub each night.
37:51Clearly a different attitude to drink driving back then.
37:54But he often struggled to see the dark road on his way home.
37:58One of the tricks he used to have was to follow the tram lines.
38:02Because on your headlights of your car, it would pick up the metal and just glimmer back at you.
38:09But in 1930, buses were brought in, the tram lines were removed and Percy was left with a treacherous drive home.
38:17Until one night.
38:18They were coming home down a very steep road with a precipice on the right-hand side that looked down into the valley.
38:31I mean, it really was steep.
38:34And he suddenly glimpsed a reflection on the side of the road.
38:39Yep, you guessed it.
38:41The headlights picked up the cat's eyes and it stopped within inches of falling over this precipice.
38:53And that's when he got his eureka moment.
38:56Percy realised if he could replicate the special surface of a cat's eye to reflect his headlamps, he'd be on to a life-saving and money-spinning winner.
39:12Well, it was sort of trial and error.
39:14I mean, the first one he made, he had the eyes sort of stuck up.
39:19He realised that was wrong.
39:21He got to bring the eyes in line with your headlights hitting them.
39:25Eventually, Percy cracked it.
39:28His feat of feline engineering had a cast iron base with the now familiar rubber case and glass reflector beads.
39:36They don't need maintenance, they don't need batteries changing, nothing.
39:41It's just a really simple, brilliant idea.
39:45In 1935, Percy patented the invention and started his company Reflecting Road Studs Limited.
39:55By the 1960s, Percy's company was making 2,000 cat's eyes a day.
40:01And he could finally afford some of life's finer things.
40:05He didn't change his life. He didn't move out.
40:08His big luxury was he bought a Rolls-Royce.
40:14It was the most expensive Rolls-Royce that they made.
40:19Percy died in 1976 at the age of 86.
40:25But Glenda's family still run the company and his life-saving cat's eyes are still on roads all over the world today.
40:33We're just very proud really, just to think that this young lad who left school at only 13 years old could do that.
40:43The Prime Minister James Callaghan, on his retirement from the House of Commons, said that the thing that he was proudest of was he sanctioned putting cat's eyes in the road.
40:57Motorways are great at getting us from A to B fast and efficiently.
41:06But without our next component, you might struggle to make it to B at all.
41:11Guiding us where we want to go.
41:15It's Motorway Signs.
41:25OK, so what does it actually say?
41:29I'm trying to guess where it is.
41:31Oh, is that the other half of that word?
41:32That is, yeah.
41:34Oh, so darling. Darling.
41:36Darlington, that'll be.
41:38So, yeah, so that's half the sign.
41:41This is only this little section of this?
41:42That is, yeah, the top left-hand corner of the sign, yeah.
41:45This is much bigger than it looks when you're driving past it.
41:47Yeah.
41:49This is like the signs of a house.
41:50Yeah, well, it's four metres by four metres, roughly, this sign.
41:53A small house.
41:54A small house, yes, exactly.
41:56That is David Church, operations manager for Royal British Legion Industries.
42:02Builders of Motorway Signs.
42:07We've done some bigger signs than this.
42:08I mean, this one is about 16 square metres.
42:11We've done a sign that's 100 square metres, yeah.
42:14It went over four lanes of the motorway.
42:16OK, now he's just showing off.
42:19At 70 miles an hour, you travel over 100 feet per second.
42:25So, big signs and big typeface are the order of the day.
42:30As is attention to detail.
42:37There was once a sign in Wales.
42:39Now they have it in English and Wales.
42:40Yes, yeah.
42:41And they'd obviously send it off to a translator and printed what came back.
42:43But, unfortunately, it was just the out of office for the translator
42:45that they had finished on this mansion roadside.
42:47And it was in Welsh.
42:48In Welsh, exactly.
42:49In Welsh, exactly.
42:50No one realised.
42:51Yeah.
42:55So, after David does a final spell check,
42:58it's time to make sure his gargantuan sign fits together.
43:05Making us do manual labour.
43:06I'm not OK with this.
43:07Look at that.
43:15I mean, that is massive, isn't it?
43:16It's big, isn't it?
43:17Yeah.
43:18And this is one of your dinky ones?
43:19This is one of the smaller ones.
43:20This bit over here.
43:22It's like the size of a single bed.
43:30Today's iconic motorway signs are so well designed,
43:33we take them for granted.
43:35But the road to clear signage was long, bumpy,
43:38and littered with accident-prone cyclists.
43:46Early road signs were just rocks with distances carved into them.
43:51But as the bicycle took off in the 1880s,
43:55cyclists struggled to read them at speed,
43:57leading to frequent crashes.
44:00And so they started putting up danger boards
44:03to warn of hazards ahead.
44:07A few decades later,
44:08motor cars were tearing up the tarmac,
44:10bringing new hazards and even more signs.
44:16Soon, the roadside was littered with a mind-boggling array of signs
44:20in all different sizes and colours and fonts.
44:26Exasperating, isn't it?
44:27But the arrival of high-speed motorways in the 1950s
44:31made sorting out this sign anarchy a matter of urgency.
44:41I mean, the signs were appalling and I think quite dangerous.
44:47That's Margaret Calvert, OBE, Queen of the modern road sign.
44:51She was close to dropping out of the prestigious Chelsea School of Art
44:57when graphic designer Jock Kinnear came to the college.
45:00So he came in one day a week to give us some idea of what graphic design was about.
45:09He set projects which involved a bit of lettering.
45:13I mean, I didn't know anything about typefaces then.
45:15The other students weren't in the slightest bit interested, but I immediately latched onto it.
45:22I would take work home and I always looked forward to Mondays.
45:27Jock was so impressed he offered Margaret a job.
45:33And his firm had just landed the contract to design signs for the UK's first motorway.
45:39Well, the signs that existed, they were absolutely chaotic.
45:44They just wouldn't have worked.
45:46Not to mention, impossible to read at motorway speeds.
45:55The government had helpfully instructed the pair to use the same typeface as the new German Autobahns.
46:01And, of course, we completely ignored it.
46:06We just went ahead with our own version based on a typeface called Accidents Grotesque.
46:15Interesting choice for a road sign, Margaret.
46:18And I can remember changing it completely and, eventually, that's what we used.
46:23Their newly designed typeface was simply called Motorway.
46:29And it was unique in that it used lowercase lettering.
46:36Well, lowercase, simply because if you read a place name, like, say, Birmingham,
46:43it's got a shape to it, because you've got the capital B, the H and the G.
46:49So that gives you a word shape.
46:50But if it's all in capitals, there's no shape to it.
46:56The shape didn't just make the sign look elegant.
46:59It also made it much easier to read at speed.
47:03At the right decision-making moment, the place name is formed and you can read it instantly or very quickly.
47:13Alongside the new typeface, Margaret was also developing the colour of the new motorway signs.
47:18The actual colour of the signs was important from a point of legibility.
47:24White letters reflect light, so they are stronger.
47:28So your eye goes to the actual place names and I thought they look good in the English countryside,
47:36which is all greens and blues and sometimes grey when it rains.
47:40The radical redesign provoked strong reactions from the public.
47:46Opponents called them crudely coloured, overpoweringly large and even designed for lunatic drivers.
47:52And rival topographer David Kindersley was so outraged by their signs, he tried to get them replaced with his own design.
48:01We just felt he was interfering. He wasn't commissioned to do the job, so that was that.
48:10But we never felt threatened by it.
48:12This topographer war eventually hit a full stop in 1958, when Jock and Margaret signs were installed on the Preston Bypass.
48:24And then rolled out to every motorway across the country.
48:29Remarkably, their design has changed very little since.
48:35I think the signs don't date. That's the important thing.
48:40They've got a timeless feature about them.
48:43I think I'm just very lucky to have worked on things that have proved life for people in the public realm.
48:51So just how easy is it to speed read Margaret signs?
49:06I'm heading to this service station car park to find out.
49:11Oh gosh, I genuinely feel like a spy.
49:14Yeah, I see you.
49:15They look good.
49:17That is Professor Polly Dalton from Royal Holloway, University of London.
49:22She's given me these fetching glasses with special cameras inside to track my eye movements.
49:32That red circle there is your eye movements and so you can see them as they move around the seams.
49:38Very clever.
49:40Motorway signs are cleverly designed to be read in a maximum of four seconds.
49:46Let's see how long it takes me.
49:48We're going to be looking at your eye movements as you drive to get a sense of how often and for how long you're looking at the motorway signage.
49:57Using just the road signs, I have to loop around and find my way back to these services.
50:04Because who doesn't want to spend more time in motorway services?
50:07Am I not allowed to use that now?
50:10No, this is all about the motorway signage, so yeah.
50:12It's old school.
50:14Yeah, exactly.
50:22So, I am going to come off at the next junction.
50:26Let's have a look. Where are we?
50:28Now, there's a bit of roadworks going on here.
50:30There's a lane closed.
50:31Yeah, this is a really good example of how much information there is for us to process when we're driving.
50:38On top of that are all the other distractions crying out for our attention, like the traffic.
50:44This is the thing about the M25 is like trucks to your right, trying to test.
50:52Or the weather.
50:54These kinds of driving conditions, they just put even more demand on the driver.
50:57Mmm.
50:59It would be really interesting to see what the data says, because it feels like I'm not actually looking at the signs too much.
51:06The end of the test is in sight.
51:09OK, Clacket Lane Services.
51:11One mile.
51:12I'm going to linger for that four seconds to think about the service burger that I'm going to have for lunch.
51:23And the results are in.
51:26We can have a look at where your eyes are going on the scene.
51:29You're spending most of your time looking roughly in the middle of the road, which is giving you the good sense of awareness for the road around you.
51:35You're doing some looking over at your mirrors.
51:38And then we have seen a few movements over there to the signs as you go past them.
51:42Let's see. Yeah, there you go.
51:43So you have a look at that one over there.
51:45The data shows I spent an average of 2.3 seconds looking at each road sign.
51:51Well inside the four seconds.
51:54Thanks Margaret.
52:01Our motorways are marvels of ingenuity.
52:05But we can't ignore the impact our need for speed has on the planet.
52:10Instead of the end of the road, though.
52:13Maybe motorways are the fork in the road, leading us to a greener future.
52:24Driving creates around a tenth of global CO2 emissions.
52:30Electric vehicles offer hope, but the challenges of charging are a big problem.
52:37And so I am in Milan to try out a new kind of road, one that could be the answer.
52:44Next time round, we'll get a Ferrari for you.
52:48Unbelievable.
52:52That is Gilad Chiron of tech company Electrion.
52:56He thinks that their new self-charging road could make range anxiety a thing of the past.
53:02Triple clap!
53:04And, of course, I want to drive.
53:09Have they told you that I'm a terrible driver?
53:14I'll hang on.
53:15I'll hang on.
53:17Do.
53:21The 35 degree heat and broken aircon are also not going to help.
53:26But at least my mission is simple.
53:28Just follow the blue lines.
53:30So, Hannah, you know what's special about this car?
53:33Besides being nice and cosy.
53:36Cosy is one word for it.
53:38What's happening on the background is that every time we're driving over this specific lane,
53:44we are wirelessly charging the vehicle while we're driving.
53:49Yes, it charges as you drive, with no wires or charge points.
53:54Show me.
53:58OK.
53:59So, here, you see this?
54:00It's charging.
54:01OK, so it's charging.
54:02So, if I come off...
54:04And...
54:05Oh!
54:06Wait.
54:07It diminishes to zero.
54:08Yeah.
54:09Go back on.
54:10And if I go back on...
54:11Amazing!
54:12Look at that!
54:14So, what is the secret to those blue lines?
54:17Spill the beans, Gilad.
54:19Just look at those toys when we were kids and he has those little cars that went on the electrified road.
54:26Like Skeletrics kind of thing.
54:27Yeah.
54:28It's the same principle.
54:30OK, but those toy cars have got, like, the little wire brushes that hang down from underneath.
54:34If I turn this car upside down, will I see the same thing under here?
54:37No. What you will see is basically a receiver.
54:39The receiver is a 40 centimetre wide electromagnetic coil linked to the car's battery.
54:49Another coil in the road transfers power to the car.
54:53This is the bit in the road.
54:54This is the coil segment.
54:56It's super simple.
54:57It's basically rubber with copper in it.
55:00Buried 20 centimetres below the surface, the coil segments are linked together in a row.
55:06When high voltage electricity passes through them, it creates an invisible magnetic field.
55:14When the car's receiver passes through this field, it converts it back into electricity,
55:20charging the battery quicker than the vehicle uses it.
55:27You could just carry on driving without ever having to stop to charge.
55:30Never.
55:31Wow.
55:34Gilad's next step is to get this tech onto a motorway for real.
55:39Like all new technology, right now it's expensive.
55:441.6 million pounds a mile expensive.
55:47But Electron hope to halve that once it's scaled up.
55:50And then they'll recoup their costs from the vehicles that use it.
55:53The whole idea, eventually, is to install this where the buses and the trucks go.
56:00They need a lot of energy and they will sell them the charge.
56:04And once it's in the road, you don't need to touch anymore.
56:08No maintenance here.
56:10Electron plans to build longer stretches of electric road in Italy, Sweden and France.
56:15But don't get too excited, the fully wireless motorway is still a few years off.
56:30Nobody quite knows what lies ahead for motorways in a cleaner, greener world.
56:34A symbol of progress and future.
56:38They have been adapting for over 70 years and will need to keep evolving.
56:43Just as long as no one changes T-Bay services.
56:46I think it's really notable that all of those decades ago, when motorways were first conceived, that world sort of doesn't really exist anymore.
56:57So many more cars on the roads now than there ever were.
57:01And that means that all those invisible bits are going to become ever more important for motorways to remain fit for purpose going forwards.
57:10The Open University has produced a free poster exploring what lies behind the genius of some everyday objects.
57:22To order a copy, call 0300 303 2061.
57:27Scan the QR code or go to bbc.co.uk forward slash secret genius and follow the links to The Open University.
57:34The Open University.
58:04Amen.