Environmentally, what keeps the trucking industry going?

Railroads have to pay to maintain their own tracks. Truckers use public highways.

The Interstate Commerce Commission killed the rails, mostly, but controlling freight rates interstate because they needed long-haul trucking to help pay the costs of building interstate highways by taxing the trucks.

But a single freight train can haul 500, 1000 trucks from coast to coast without damage to the highways, using a lot less fuel, and without a trucker in every cab.

Rails made since when trains were invented, and they still do.

As for keeping products safe from spoilage, trucks and rail both have something called 'refrigeration'. Modern innovation.

Trains work fine if you are sending a large amount of goods from close to point A to close to point B and there are short haul truckers at each end of the trip to make the pick up and deliveries. Planes work equally well for small items such as over night packages but they also need trucks at both ends to make the pick ups and deliveries.

But the interstate truckers pick up directly at Point A and go directly to Point B. This is the fastest way to get goods over land also one of the most secure. You can have BILL the trucker pick up at the factory, BILL the trucker drive the goods to the destination, BILL the trucker present to deliver the goods, all the time BILL the trucker truck is being monitored by his dispatcher to help ensure timely delivery and prevent theft. Since BILL the trucker is entirely responsible for getting the goods delivered intact and on time, he has great pride in his work.

But as far as environmental issues, I can not wait until they come out with a hybrid truck. Imagine an 80,000 truck getting 10 miles per gallon consistently. I am surprised the truckers are not yelling and screaming for it already.

Trains do get used for a lot of things. But a train can't pull up to your local grocery store and deliver goods. Also, many towns and communities are not on railroad tracks. Trains, and the railway system in America, are designed to take a large amount of something (say cars from a factory) and take them to a distribution center. From there, they need to be taken to the individual stores that will be selling the items. There are usually a few more stops, but that is the rough idea of it.

To do what you want, deliver goods to all of America via the trains, you would need tens of thousands of miles of new tracks to connect communities as well as redesign how the rail system works. You can have a train stopping every 10-15 miles at each community to drop off goods. Things would get extremely backed up, with more trains behind having to stop. Also, the efficiency of the train would be decreased having to stop so often. Trains are efficient when they can maintain a decent speed and not have to change speeds often. For an average train to make a complete stop, it can take a mile of slowing down and braking. It takes just as long, and sometimes longer, to accelerate back to speed. That is a lot of wasted fuel.

We may be able to better use our rail system, but it would take a lot of investment and time to get what you are hoping out of it.

A train can move cargo at about one-sixth the energy cost of truck freight. Therefore, as energy prices rise, train freight becomes more cost-effective.

Since trains are not everywhere and installing and obtaining new rights of way are extremely costly, trucks have to haul freight in many areas. As you note, trucks are necessary for short hauls such as from a train yard.

Although a train can be slow, trains can haul so much cargo that their lack of speed is very much offset by their volume. Think of it like this. If a train can haul 50 times as much cargo as a truck, even if it is only one-tenth as fast as a truck, it can still transport five times the volume of product in the same amount of time.

Trains are essential for hauling things like coal which are extremely heavy, voluminous and shipped in great quantities.

Trains are very slow. To keep up with supply and demand, the individual truck can get the goods there a lot faster.

Especially in the matter of perishable goods.

Milk, veggies, meat would have a higher occurrence of spoilage if trains were used.

EDIT:

We all know about refrigeration, but all perishable goods have a shelf life. The longer it takes to get to market, the shorter the time it can stay available for sale. The expiration date is what it is, so if it takes a shorter amount of time to arrive it can stay for sale to the public longer.

Also, imagine ordering something on line and having to wait for it to ship by rail. We live in a society that wants everything done yesterday. Waiting for the train is unacceptable to most people. Not to mention the collapse of the economy. No FED EX, no UPS, and what about the US Post Office. Hundreds of thousands, if not millions, of jobs lost.