Would anything happen if I drove a car into a moving train?

Obviously, it wouldn’t be a good idea, and I’m not going to try it. And obviously, I have an idea of what happens when a car gets in the way of an oncoming train (the train’s pretty much going to win).

But imagine this: I’m stopped at a railroad crossing. One of those great big freight trains - the ones with about six thousand cars that takes forever to go by - is chugging along the tracks. Assume I’m in a typically-sized modern car, and in a moment of insanity, I decide I’m tired of waiting, stomp on the gas, blow through the little barrier arm, and drive straight into the train.

Obviously I’m not going to get anywhere other than awfully close to the steering column. But what would the effect on the train be? Would it derail? Would it necessarily slow down? Would it just keep chugging along?

Or what about the same situation, but with a smaller, lighter train - an Amtrak train, or even a light-rail commuter train?

There is a decent chance that, as your vehiclewedges under one of the freight cars (a long train is more like 150+ cars, not 6000 BTW), the freight car’s truck (its wheels/axle/spring assembly) will jam against the vehicle side, and possibly derail.
Average laden freight car weights are approaching 120+ tons (not counting multi-platform intermodels - those articulated container/Trailer carrying cars weigh less) means you probably won’t knock over a freight car directly, but still your vehicle jammed under the freight car could act as a wedge, giving mechanical leverage, and could topple the freight car over (and the following cars may derail also). Of course you need to take train speed, track conditions, etc into consideration, and this is discounting running something like a steel-carrying semi with a much higher weight into the freight car, which changes the calculations…
I think LRV and streetcars generally win against road vehicles, and are usually low enough that vehicles cannot jam under the side (but may cause other damage)

Nothing would happen to the train. There’s a very small chance of a derailment, which would break the train and set an emergency brake application, but the chances of that happening are fairly slim.

In reality, what usually happens is that the freight train drags the car along, the engineer being none the wiser.

Operation Lifesaver presentations include a slide to try to illustrate the mass difference between a freight train and a car–basically a car is to a train as a Coke can is to a car.

Unfortunately, people do drive into moving trains; this woman was lucky–the train dragged her car for three miles while she used her cell phone to call for help, but all too often, the driver isn’t as lucky. http://www.nytimes.com/1999/03/31/us/national-news-briefs-truck-hits-car-car-hits-train-driver-calls-mom.html

A smaller, lighter train, such as an Amtrak passenger train, would do the same thing, although since there are passengers and conductors aboard, they’d hear/see the collision and either pull the brake cord or alert the engineer. In reality, passenger trains (other than inner-city light rail) are pretty heavy–far heavier than passenger trains in other countries. This is because the FRA has strict requirements for buff strength, weight, etc. That’s also why it’s difficult for the United States to purchase off-the-shelf passenger equipment from other countries. Unless there is a total separation between freight and passenger, it usually requires so many modifications that it becomes more feasible to simply design something new.

Odd, my post duplicate…can a mod delete this one?

Since you can’t gain sufficient speed to increase the impact force of your car (think of a bullet fired from a gun versus thrown at you) then it becomes a function of the density of your car. Most likely you would wedge the car under the train and it would drag you along with little effort or bounce off the sides of wheels in a broadside manner. If the car was low enough so that it slid under the carriage of the train then he wheels could hit it and derail.