I live in northern Idaho, The deck is 12x16, there is just an area about 5 feet by 15 feet to plant it in, I would prefer that it has a deeper root system because of the side walk and steps. I would like color in the fall, but I do not want a mess the rest of the year either.

It is going to be hard to find a shade tree to fit into a space that is 5 x 15. I am not completely sure exactly what hardiness zone you live in but you may want to think about a honey locust. They are a full size shade tree but they provide a nice filtered shade. They turn a nice gold in the fall and the leaves are really small so when they drop in the fall you just have to run a mower over them and they disappear. As for your concern about your sidewalk as long as it was installed properly a tree shouldn't wreck a sidewalk.

No special plant degree from me, I'm afraid, the last suggestion sounds nice....but a thought I had was to check out folks that had decks already in your area. I allowed a volunteer Swamp Maple or Tulip Poplar to come up near my new deck and the leaves are huge, make a dreadful slim-y mess when they fall, rot and get rained on, and leave a leave shaped stain on the wood.
I live with it, because the tree has a 10 year head-start from a seedling, and I have no bid 'druthers on one I love more for my zone. My point is just to be sure whatever tree you choose will not do the same uggie thing to your deck!
Good Luck!

Pecan trees make great shade trees. Birch and Elm are nice as well. I have all these trees in my yard and sometimes they produce too much shade.

need a lot more info...where do you live, how big is the deck, how much shade do you want, are there other trees near, are there utilities near, plumbing, all kinds of stuff....

i like non-fruiting bradford pears. sounds strange? non-fruiting cause who wants the dears visiting to eat pears. also, it is medium sized, has beautiful autum color, beautiful white flowers in spring, and glossy dark green otherwise. check it out...