I caught the end of Back to the Future 3 on cable TV and something dawned on me.

Originally they were on a time schedule to leave because they knew that one of them was going to be shot and killed by Biff by a certain date.

But after Biff was arrested, why did they still need to rush to catch the train and everything? Essentially don't they have all the time in the world now, including enough time to wait for the bridge to finish construction?

You're probaly right. I'm guessing it was just a plothole of sorts, but one explanation might be that (IIRC) they already placed the Delorean on the tracks. Had they not rushed to catch the train the train would have smashed into the time machine leaving Marty and Doc stranded forever. Right?

The Delorean was on the side track. If Doc & Marty hadn't hijacked it, it would have stayed on the main track & not been near the car. Of course, the longer they stay in the past, the more likely they would alter time. Doc was already freaked out that they had altered time by saving Clara.

They could have put the car closer to the track split to give them more room to get to 88 but then the movie wouldn't have been as exciting.

because 1885 sucks and they wanted to leave

There was only about 15 minutes left in the movie, so Marty had to get back to 1985 before the movie ended.

They still needed to go back in time so Marty could fix the replacement Jennifer.

Claudia Wells

Claudia Wells < Elizabeth Shue

Maybe they were so caught up in trying to get back to 1985 that they forgot that Biff being caught would give them time.

Or Doc was really super freaked about possibly changing the future given the events of BTTF2.

Hell yeah.

what if Marty woulda slept with his great great great grandmother and got her preggers?

Melora Hardin > Both

Well, differ'nt strokes for different folks.. the switch always bugged me and I always preferred Claudia. I never did like Shue.

Anyways the switch was kinda like Wesley Snipes being replaced by Omar Epps in Major League II.

For this role, I agree.

fyi - detailed back to the future timeline

It seems you've found the only hole in the plot of these three films.

Holy Crap! I had a migraine after reading Timeline 0.

Melora Hardin - I learn something new here almost everytime.

This -----> http://www.mjyoung.net/time/index.htm site also has tons of info about BTTF 1-3 and many other 'time travel' movies...

Here's another plot hole I found when watching this movie a while back. When Marty arrived in 1885 the fuel tank or lines were damaged resulting in no gas. Why didn't they just get the gas out of the Delorean that the Doc had left hidden in the mineshaft for Marty to retrieve in 1955. They would not have had to even put the car on the tracks to get back through time. 1955 versions of Doc and Marty could then have put gas in the car to get back to 1885 to start the cycle over.

Because then Marty from 1955 wouldn't be able to go back to 1885?

You know what I don't understand? First, Doc in 1955 is adamant that he doesn't want to know too much about his future. Then he reads Marty's note and wears body armor. Then, he blatantly changes the future by whisking Marty to 2015 to impersonate his son. Then in 1885 he's back to not wanting to change the future again - to the point where he won't even tell Marty about the car crash he's going to get in as soon as he gets back home!

How do they explain Maggie McFly in 1885 looking exactly like Marty's mom in the future? Techinically, they shouldn't have looked alike at all, since they wouldn't have been related.

I know the answer is going to be that they allowed Lea Thompson to play the role so they could have Marty waking up from unconsciousness to the same face once in each movie, simply as a "recurring gag", but I never thought it made much sense.

Wrong. There are TWO DoLorians around (one's buried in the cave). Sure, they'll create a paradox if they use DoLorian #2, but who cares as long as "our" Marty gets home.

I'm guessing Doc would have drained the gas tank before hiding it so it wouldn't damage the fuel lines having gas sitting in it for 70 years. He might have used the gas for some other reason before Marty got there He had all that futuristic stuff in his barn so maybe the gas was used in building those.

I wrote virtually the exact same thing to STARLOG magazine back in 1989. The answer I got? A) They didn't want to create any more paradoxes and B) It would have been a very short movie!

Not to mention the fact that when all was said and done, and the time machine was destroyed just like Doc wanted from the beginning, he truns around and builds ANOTHER freaking times machine to tool around in!