What must be understood is that truck driver training is big business.  It is an industry all of it's own.  Anybody can start a school and there are no guidelines as to what must be taught, how they teach it nor who does the teaching.  Thousands upon thousands consider a truck driving career every year and there are many who capitalize on this and exploit the job seekers.  For example, here is a web site that will sell you CDL testing material for a cool $95.00 and a "guarantee" that you will pass the CDL written tests.  Well, friends, with a little bit of web surfing, I was able to easily locate the CDL Manual online... for a far more reasonable price of $0.  The written tests are based upon this manual.  This is all you need in order to pass any and all of the written tests.

Here is a free gift, in .pdf format, yours for the downloading: 

You can also practice taking tests for free at any of many websites.  Try: