I help designers improve their games.
My kids like the game, but dislike the competitive aspect. My 6-year-old made up cooperative rules which we have been playing. Here are the changes:
Take turns, as before, but you are working as a team.
If an item falls off, put it into the 'troublesome trucks' pile.
If you draw a card that cannot be used (e.g. a crate when the crates are gone), discard it and the same player goes again.
If you draw a location card, rotate Thomas as usual, then place the location at the end of that track.
When all the tracks are complete, the game ends. Count the number of items taken by the troublesome trucks and compare it to the number on Thomas, ignoring any items that were entirely unused. If the players have more than the trucks, the players all win. If the players have less (or are tied), the players all lose and the troublesome trucks win.
To make the game more difficult, count each item the trucks get double.