The remaining mechanics and technicians maintained the fleets of trucks and other equipment for manufacturing, construction, or other companies. A relatively small number were self-employed. Nearly every section of the country employs diesel mechanics and service technicians, although most work in towns and cities where trucking companies, bus lines, and other fleet owners have large operations. Employers prefer to hire graduates of formal training programs, because of these workers' head start in training and their ability to quickly advance to the journey mechanic level. Many community colleges and trade and vocational schools offer programs in diesel repair.
Programs vary in the degree of hands-on training they provide on equipment.
Some offer about 30 hours per week on equipment, whereas others offer more lab or classroom instruction. Training provides a foundation in the latest diesel technology and instruction in the service and repair of the vehicles and equipment mechanics and technicians will encounter on the job. These programs also improve the skills needed to interpret technical manuals and communicate with coworkers and customers. Increasingly, employers are working closely with training programs, providing instructors with the latest equipment, techniques, and tools and offering jobs to graduates. Whereas most employers prefer to hire persons who have completed formal training programs, some mechanics and technicians continue to learn their skills on the job.