[Hmm, give him a second while he mulls this over. It's been ages since he actually hit that route, after all...

Well, right off the top of his head...]

The most common Pokémon you'll bump into are Pidgeys, Rattatas, Sentrets, maybe a couple Hoothoots at night. Nothing too exciting, but you might have better luck if you have your Pokémon ram into the trees. Maybe you'll bump into something cool, like a Heracross.