INTRODUCTION W hen you are ready for school each morning do you walk pedal your bike ride in a car or take the bus Imagine hopping into your own transporter powered by electricity or perhaps solar energy and quietly gliding down the street If there were too many cars on the road you could simply steer up into the air and fly the rest of the way Other vehicles would be zooming around too but everyone would be following the rules of air space The Jetsons were a cartoon family that lived in space flying their small personal ships from place to place Reality might someday catch up with this fantasy especially if people set up colonies to live in space For now you’ll have to stick to traditional modes of transportation such as cars and buses as you go to school the grocery store and other destinations But in the future you might find yourself racing across the country on a high-speed train traversing the ocean in a personal submarine or rocketing to the moon For thousands of years the way people travel has improved by leaps and bounds Instead of walking along paths beaten down by animals people can drive at high speeds on smooth paved highways One hundred years ago the very first cars and airplanes were being developed today scientists are eyeing trips to Mars What does the future hold next 4
Although people have long dreamed of the day when flying-saucer type transportation will become reality most transportation will remain on the ground for a while
ransportation refers to the movement of people or things from one place to another To travel efficiently people need two things a vehicle for propulsion such as a bicycle horse or car and infrastructure including roads highways and bridges on which to travel Ancient people traveled by foot on dirt paths trampled by animals They used elephants camels and other beasts of burden to pull cargo on sledges two flat boards that slid along the path The earliest known road is the Sweet Track estimated to be 6,000 years old Discovered accidentally in 1970 by an English peat cut ter named Ray Sweet the road was built from tree branches and planks made from tree trunks and likely was constructed to help people cross the wet lowlands of southwestern England The ancient Romans improved on road building when in 312 B C ruler Appius Claudius Caecus ordered the construction of a vast highway network that would eventually include 370 major roads covering 50,000 miles 80,470 km Romans often built their roads by layering packed earth stone blocks and sand Some of the sturdiest were five feet 1 5 m thick with slight arches at the middle so water would drain off the surface of the road Today’s roads are built with this same cambered design The Silk Road was the most famous of all ancient road systems Used for nearly 10 centuries the Silk Road ran through China and central Asia and also led to India Saudi Arabia and Egypt Along the T C H A P T E R O N E C HAPTER O N E 1 WALKING WHEELS AND WORLD TRAVEL 6
Stone and wood formed some of the earliest travel routes including ancient Roman roadways left and the Sweet Track pictured in reconstructed form below
