Are you ready to find out even more about how our roads came to be? Just continue reading below!
John McAdam was the first ‘modern’ road builder and gave his name to the Macadam surface in the 1800s. His brilliant innovation was realising that roads did not need massive stone foundations. By ensuring that the top stone surface was made with stones smaller than the tyre width he innovated a smoother running surface, but there was still a dust problem. Eventually, someone took the top surface and mixed it with tar and leaving us with a tarmacadam road, that’s tarmac to you and me.
Thanks to the introduction of tarmacadam roads we had a road on which our vehicles could perform their different functions. But as we moved into towns and cities we needed to something to separate people from the road. For this, we used the raised pavement. Pavements have been around since Roman times but began to play a necessary role as our towns and cities became busier with vehicles. To protect the edge a solid granite kerb was added. In fact, if you look at a kerb you will most likely see black tyre marks upon it, visible proof of the job the kerb does in defending the pavement!
Stay tuned for more on how our roads came to be.
We’ve talked about how we and our bodies shaped driving but what about how we came to have the modern roads we drive on today?
Before the development of modern communications, roads were what connected us as people. As such, they were driven by economic, political and military forces. People needed to get produce to market. The government wanted to tax and enforce its power on those it controlled and from the government's point of view, the more people it controlled, the more tax is raised and the more powerful the government became.
The first roads were tracks and people themselves carried the loads. We then started to domesticate animals, for food, company and to help grow crops. It was inevitable that we would then start to use animals to help carry loads. The development of further transport was limited by the environment, would an Inca peasant working on his mountainside terrace need and be able to use a cart?
As we discovered mechanical advantage, animals began pulling our carts and we wanted better tracks to get us from A-B. The compacted dirt road pretty soon turned to mud in the rain and dramatically increased its resistance to a turning wheel. The wheel itself, if too narrow would sink down into the road and in the dry, dust became a problem.
The solution to the sinking wheel was to be a harder stone road. Big stones at the bottom becoming smaller at the top. The ride would not be smooth but you and the load were getting to your destination. Rainwater was still a problem but this was solved by John Metcalf. He did this by giving the road a camber and good drainage.
Next week we’ll dive deeper into how and why the roads we know today came to be.
Have you ever thought about why cars are designed the way they are and driving is how it is?
Last week we talked about speed limits, seeing people in time and avoiding them. But what about us, the driver, how are we kept safe if it all goes badly wrong?
Besides the interior of the car being made softer to minimise damage to ourselves. We wear seatbelts. These belts are designed to work with your bones. Specifically, the diagonal should go across your collarbone and the horizontal across your hip. The important thing is your bones are solid and will, along with a properly fitted seatbelt, protect your internal organs.
Over the years cars have grown head restraints. Your head is a large lump of bone with a pointy bit at the back. This will rotate backwards unless contained by the head restraint. Not adjusted properly it could become a very real pain in the neck.
How you hold the wheel will have a very real effect. If you’ve adjusted your seat properly your arms will be slightly bent. They will be your shock absorbers. Having two hands on the wheel at 10 and 2 will prevent you twisting violently if you have to stop very suddenly and unexpectedly.
In part 1 we talked about the eye. The eye itself sits in a socket which defines your field of vision. You can measure your own field of vision by extending your arms and sticking your thumbs out. Move your arms out to the side holding your head still. Stop at the point your thumbs start to disappear and this should give you a range of 180 degrees plus.
Having 2 eyes gives us a depth of vision. However, you can still drive an ordinary car with only one eye. Put your left hand over your left eye, extend your arm and thumb to the point where it disappears on the right. Now track its movement as you move right to left. Your view of your thumb to the left is now only limited by your nose.
So in an ordinary car even with only one eye, you will be aware of the width of your vehicle. You cannot drive larger, wider vehicles unless you have some vision in your defective eye. This again is so you are aware of the width of this much wider vehicle.
Stay tuned for more on how our bodies shaped driving.
Inside your eye, you see with a series of receptors called rods and cones. There are about 20 million rods per eye which measure movement and contrast. They are responsible for your peripheral vision and have a limited response to colour which we will look at in a minute.
There are about 6-7 million cones which measure colour and because of their faster response to the brain give more detail. Due to this sensitivity, the eye is in continual motion building up a picture of what is happening. This is what we want our learners to do.
These colours to which the cones respond are red 64%, green 32% and blue 2% which are the primary colours. This gives us red for danger, green for safety and blue for authority. Yellow is made up of red and green. From this, we now have the colours of the traffic lights and road signs. The rods in our eyes have no response to red light. This means at night when our eyes have adapted to the dark, a red warning light is not going to wash away the rest of our vision. Because there is some response to blue from the rods we become very aware of blue lights from the emergency services.
Eyes are sometimes described as windows to the soul. A professional eye examination can also be a window to good health. These checks are capable of detecting a range of conditions such as high blood pressure. They should be done at least every two years. Remember your eyes and vision are key for driving so have a think, when were yours last checked?
Have you ever thought about why cars are designed the way they are and driving is how it is? Well, we’ve got some more answers for you.
As our vehicles moved on from the humble horse and cart to faster mechanically propelled ones and in much greater volumes, we started to introduce a series of rules. These rules have to work for us as driver and people. So why are most maximum speed limits worldwide nearly always 70 mph (113 kph) or thereabouts?
Besides the physics of it that says the faster you go the more room you need to stop safely, what does 70 mph limit give us? The 100-meter stopping distance is about as far as you can still see a person's face. This means we can react to another person and we would also know that they have seen us. Hopefully, they would be getting out of our way now or we would have a chance to stop without killing them.
This ability to see a person’s face at 100 meters gives us street lamps just under 100 meters apart. At night time if you are walking, you want to be able to have some idea of the people walking around you.
The 30 mph speed limit is in place so that in the unlikely event that your car hits a person they have just over 50% chance of survival. If you drop the speed down to 20 mph that becomes 95%. This illustrates how our bodies react to speeds and impacts from cars.
Stay tuned for more on how our bodies shaped driving.
Recent Blog Posts
- Roads (PART 2)
- Roads (PART 1)
- How our bodies shaped driving - Part 5
- How our bodies shaped driving - Part 4
- How our bodies shaped driving - Part 3
- How our bodies shaped driving Part 2
- How our bodies shaped driving: Part 1
- Want to Learn to Drive?
- The Law and learning to drive
- The 4 Considerations when driving.
- Safety when driving: The 3 Zones of Safety
- SHOW ME TELL ME PART 4 - MOVING
- SHOW ME TELL ME PART 3 - INTERNAL CHECKS
- Show Me Tell me Part 2 - EXTERNAL CHECKS
- How to choose a driving instructor?
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- Are you ready for your driving test?
- How the driving test is unique.
- Death sentence for pedestrians.
- Different ways of looking at the driving test.
- How to beat driving test stress.