Why people use motor vehicles
A motor vehicle is a vehicle moved by its own engine or motor, such as a car, bus, truck or scooter.
Before motor vehicles, people walked, rode animals or used carts. Today a vehicle saves time, carries heavy loads and goes door to door. Ambulances, fire engines, delivery vans and school buses all save lives or work for us.
A short history of the car
Early self-moving vehicles in the 1700s used steam and were slow and heavy. Around 1886 the first petrol cars appeared. In the early 1900s factories began to build cars on an assembly line, so cars became cheap enough for ordinary families. Later came safer bodies, better engines, and in recent years electric and hybrid cars.
Good effects on our lives
- Speed: longer trips take less time.
- Reach: villages and farms link to towns and markets.
- Trade: trucks bring food and goods to shops.
- Jobs: factories, garages, drivers and road builders earn a living.
- Emergency help: ambulances and fire engines arrive fast.
Problems when there are too many cars
- Traffic jams: a road can hold only so many cars.
- Air pollution: engines give out gases and tiny dust; some gases (like carbon dioxide) warm the Earth.
- Noise hurts sleep and study.
- Crashes: many people are injured every year.
- Space: roads and parking take land.
How we make motor vehicles better
Engineers make engines that burn less fuel, add safety devices, and build electric cars with no exhaust. Cities build buses, metros and cycle lanes. People can share rides, drive smoothly, keep the car serviced and follow traffic laws. See the lessons Principles of the car and Cars and safety.
Key formulas and definitions
- Road used by cars = number of cars × about 6 m (car + gap)
- People per vehicle: car about 1.5, bus about 40 or more
- Space per person = road length ÷ people carried
- Key terms: traffic jam, exhaust, emission, public transport, car sharing
Worked examples
1. 27 cars each use about 6 m of road. How much road is used?
27 × 6 = 162 m, about 160 m.
2. 40 people travel in cars with 1.5 people per car. How many cars? (round up)
40 ÷ 1.5 = 26.7, so 27 cars.
3. One bus is 14 m long on the road and carries 40 people. Road per person by bus and by car (6 m per car, 1.5 people)?
Bus: 14 ÷ 40 = 0.35 m per person. Car: 6 ÷ 1.5 = 4 m per person. Car uses about 11 times more road per person.
Common mistakes
- Thinking cars are only bad. They also save lives (ambulances) and move food.
- Thinking more roads always end jams. New roads often fill with new cars.
- Counting only the exhaust. Noise, crashes, tyre dust and land use also matter.
- Believing an electric car has zero effect. It has no exhaust, but making it and the electricity still use energy.