Mexico does, too. Check out the 1950 Southern Railroad silver 5 Pesos. And 2010 the Mexican 100 Pesos, polymer banknote. Canada also has a lot of old paper money with trains depicted. If you get back into old banknotes in the U.S. from the "free banking era" about 18302-60s, and some of the Confederate notes, you can find lots of train themes. Of course you can also collect "railroad" rim error coins.
There are a lot of things on the back of the state quarter program that are not on U.S. coins. You could ask the same of trumpets and bucking broncos. I can't think of a commemorative either, unless others can. And there are more objects besides. The states designed their own quarters without too much restrictions.
ebay "train" link: http://www.ebay.com/sch/Coins-World...R40|R40&ghostText=&_ipg=200&_nkw=train&_sop=3
ebay completed auctions link : http://www.ebay.com/sch/Coins-World-/256/i.html?_ipg=200&_sop=3&_from=R40|R40|R40&ghostText=&rmvSB=true|true&_nkw=train&LH_Complete=1&rt=nc I liked the 1988 Albania 50 leke train and tunnel design best.
My 3 year old grandson loves trains and in trying to get him interested in coins which is going pretty well too. He enjoys looking at them with me that's why I'm looking for train coins.
