Acerca del examen de General Knowledge (Class B)
The Class B General Knowledge test pulls from the same FMCSA CDL Manual as Class A, and the question content is largely identical. The difference is application — Class B is for single-unit vehicles 26,001+ pounds: straight trucks, dump trucks, garbage trucks, buses, and similar. About 50 questions, 80% to pass.
The Class B version of that same confusion is just as common. People pick B thinking it's the easy CDL that still lets them drive trucks. It does open real doors, just not the one most of them have in mind.
A Class B will put you in dump trucks, box trucks, garbage trucks, cement mixers, and most buses. Good jobs, steady work, and for plenty of drivers it's exactly the right call. What it won't do is let you pull a tractor-trailer, so if over-the-road freight is anywhere in your future, start with the A and skip the upgrade later.
Almost every Class B vehicle runs air brakes, and people forget they also have to pass the Air Brakes test. Skip it and you get an air brake restriction on your license, which locks you out of most of the jobs you got the B for. Take the Air Brakes practice test next to this one, not afterward.
Qué se cubre
Same Five Core Areas as Class A
Vehicle inspection, basic vehicle control, safe driving, transporting cargo, and emergencies. The rules don't change because your vehicle is shorter. A loaded dump truck still needs proper following distance, still has a high center of gravity, still requires thorough inspection.
Inspection Specifics for Straight Trucks
Tread depth requirements are the same: 4/32 inch on steering tires, 2/32 on others. Brake adjustment, fluid leaks, lights, mirrors, tires, and suspension all get inspected the same way. Class B drivers work in urban environments more often, so close attention to pedestrians and tight intersections gets tested.
Cargo Handling for Class B Vehicles
Dump trucks and concrete mixers carry shifting loads. Wet cement behaves like a partial liquid — you'll feel surge during stops and turns. Aggregate (gravel, sand) shifts differently on uneven ground. Combined with high center of gravity, this is a real rollover risk on curves.
Tight-Space Backing
Construction sites, alleys, dumpster pads. The rule on the written test: when in doubt, get out and look. Use a spotter when available. Always back to the driver's side when possible — you can see the rear through the side window.
Consejos para aprobar
- If your Class B vehicle has air brakes (most do), you must also pass the Air Brakes test or accept an air-brake restriction on your license — a serious career limit.
- Take both this and the Air Brakes practice tests before your DMV visit. Most first-time failures happen because applicants only studied General Knowledge.
- Focus on safe-driving and cargo questions — urban Class B routes test these heavily.
- Aim for 90%+ consistency before scheduling your written exam.
Errores comunes en el examen de General Knowledge B
Estos son los temas que hacen tropezar a la gente una y otra vez — tanto en nuestras aulas como en los intentos de práctica. Léelos con cuidado antes de volver a presentar el examen.
- Skipping the Air Brakes test. Almost all commercial Class B vehicles have air brakes. If you don't pass the Air Brakes endorsement, you get an L or Z restriction and lose access to most jobs.
- Assuming Class B is "easier" than Class A. The question pool is largely the same; the test is the same difficulty.
- Underestimating cargo questions. Class B vehicles haul concrete, gravel, garbage, and other shifting loads — the test covers all of them.
- Backing to the passenger side when it isn't necessary. The test, and real-world safety, favor driver-side backing whenever possible.
- Treating tight-space maneuvering as a skills-test-only topic. Several written questions cover backing technique and the "get out and look" rule.
Cómo usar este examen de práctica
Our General Knowledge B practice test draws from the same FMCSA source material your state's official CDL manual uses. Take the test as many times as you need — questions reshuffle on every attempt. After each question you'll see whether your answer was correct, the explanation, and a reference to the topic so you can study it deeper.
¿Quieres todo el contexto antes de examinarte? Lee la guía de estudio de General Knowledge B con el material completo en el que se basa este examen.