What do you mean by "kinds"? Brands, models, configurations...? In all cases, there's probably far too many to be named practically on this site... pretty much any country with an automotive industry has manufactured heavy trucks, brands have been in business, gone out of business, etc.
It depends on the weight the truck is designed to haul. "Most" trucks have 9 or 10 speed transmissions. That is the common denominator in many trucks driving down the roadways today. But, there are 13, 15, 18 and even 21 speed trucks driving down the road as well. Heavy-haul trucks such as the ones used to haul heavy construction equipment have more speeds because of the sheer weight they are hauling. Semi's pretty much don't go below at least a 9 speed transmission. Weight is the biggest factor. You can't have a 5 speed transmission attempting to move an 80,000 pound truck. The clutch would burn up the first day you started driving it if the transmission didn't burn up first. Gearing on trucks is pretty much directly related to the amount of gross vehicle weight the semi is designed to pull. However, the 10 speed is the most common simply because it is more economical when considering purchasing an entire fleet of trucks. You don't go to work for Werner Enterprised (blue trucks driving down the highway) or JB Hunt (yellow trucks) or other large trucking companies and expect to find 18 speed transmissions in them. But, you will probably expect to find an 18 speed in a truck hauling an "Oversized Load" - which could mean it is too big for the trailer or it is too heavy or usually - a combination of both.
Most semi trucks have Diesel engines and use Diesel fuel oil to operate. 6 to 7 miles per gallon is considered to be a fairly good average. Terrain and amount of load can affect this average abit.
what are kinds of economic implation? what are kinds of economic implation?
For some airlines, tickets are classified by their flexibility. Semi-flexible tickets are equivalent to airlines' semi-refundable. An economy ticket is non-refundable. Flexible tickets are fully refundable.
Take the semi-monthly rate and multiply by 12 to get the annual rate. Then take the annual rate and divide by 2080. To veryify your answer, take the hourly rate you just calculated and multiply by 86.67 and see how close you come back to the semi-monthly rate. Or, you can take the semi-monthly rate and divide by 86.67 (average hours in semi-monthly pay period) to get an hourly rate.
estimated:8-9 million trucks
It is impossible to know exactly how many semi trucks are on the road in the U.S. It is estimated that there could be anywhere from five million to thirteen million semi trucks on the road in the U.S. on any given day.
Too many to count.
2,000,000
There are many companies that write insurance for semi trucks. Some of these companies are Progressive Commercial and Geico.
A row of semi trucks. There isn't a specific name for it.
You can go to commercialtrucktrader.com to get a quote for your used semi trucks.
2 locations
You can purchase some toy semi trucks from eBay and Amazon. A lot of hobby shops that sell model trains should also sell toy semi trucks as well. Many small towns usually have a mom and pop hobby shop.
There are many independent, owner-occupied semi truck operators in the United States. Many of them sell their trucks online, and sometimes use sites such as craigslist.org and ebay.com to advertise.
There are several companies that sell use semi trucks directly or privately-such as Eddie Stobart who regularly sell their old used semi trucks as they purchase new ones.
The best place to buy used semi trucks for sale are at truckerworld dot com. They have many models to choose from with varying quality and level of conditions.