Drivers of semi-trucks and tractor-trailers can find economic opportunities in several of Oregon’s economic sectors. Agriculture is a key economic sector, producing wheat, potatoes, fruits (including wine grapes), vegetables, and nursery and greenhouse products. Semi-trucks transport these products to distribution centers and markets across the country and internationally. Although the timber industry has declined in recent decades, the state remains a leading producer of softwood lumber, creating a need for truck drivers experienced in transporting raw timber and wood products. Oregon’s manufacturing industry produces machinery, high-tech equipment, and electronics. These industries depend on truckers to deliver materials to them as well as transport their products. Finally, the Port of Portland, including Oregon’s only deep-draft container port, needs truckers experienced in intermodal transport.
As a big rig driver, however, you may have to drive with extreme caution through much of Oregon in the wintertime. Western Oregon can be rainy, resulting in slippery roads and lower visibility. Also, the Siskiyou Pass is one of the most dangerous sections of road on Interstate 5. This mountain pass has a 6 percent downgrade on six miles of winding, often foggy, snowy, or icy road with sharp curves. Interstate 84, U.S. Route 20, and State Route 58 can also become treacherous under conditions of ice or snow.
If you want to operate heavy combination vehicles like semi-trucks or tractor-trailers so you can take advantage of Oregon’s economic opportunities in trucking, you should obtain a Class A CDL. Besides the usual requirements for a CDL of any class, you’ll also have to pass the official Combination Vehicles knowledge test on the theory of operating combination vehicles. And we can help!
The Combination Vehicles knowledge test is based on the official Oregon Commercial Driver Manual (Oregon CDL Handbook 2025) – but this “study guide” isn’t that easy to study. It’s more like a reference work than a tutorial. That is why you should supplement your reading of the manual with other study tools, such as our practice tests.
This free Oregon Combination practice test is based on the official Oregon Commercial Driver Manual, just like the official knowledge test. And it’s up to date as of January, 2025. It has 25 multiple-choice questions and answers on such topics as combination braking systems, combination driving techniques, coupling and uncoupling, and pre-trip inspections. Each question comes with a helpful hint and an explanation of the correct answer. Unlike the official test, however, this free Oregon CDL Combination practice test has no time limit, and you can retake it as often as you wish to help you learn the material.