Lost World, The (Jurassic Park) - Traction for the Trailer
In the movie when Eddie is trying to pull the trailer back up with the winch, when they shoot to the tires trying to get traction, you can see the board that is there for traction. You have to look quick and if you have a good pause it is more visible. You can make it out when they are climbing over the ledge after the trailer falls off the cliff, but a little harder to see under the mud.
The other problem with this scene is that Eddie's vehicle is hydroplaning...but then they cut to a shot of it pulling the trailer back. How the heck is a hydroplaning vehicle pulling anything!