Also companies make it very difficult to get into, even if you pass your test no one like to take on rookies and makes it virtually impossible, only by chance or pot luck or working for a firm that pays peanuts and has rubbish tractor units and poor working conditions can you get in on the game.
Truck drivers money isn't horrendously poor, but a lot of the work is away from home for periods of time and it tends not to suit families, and the pay isn't significant enough.
The real money in haulage is either be an inter country driver, or a specialist, like dangerous chemicals etc.
It's also not advertised well, re pay and conditions, not many people leave school/college and want to do lorry driving, it's another one of them taboo jobs where people think only the thickos can be lorry drivers and they be better off going to uni and then working at McDonald's or Costas for the rest of there lives.
This unhealthy fascination with going to uni and only accepting those who have degrees for jobs isn't good for the UK.