homelessness

Our neighbourhood is really new, it's an industrial turned residential area, so it's a little low on amenities, and high on town homes. (It's the most densely populated area of the city) I assume, that because we are such a new neighbourhood with nothing but houses we don't have many homeless people around here, until recently. There is this one guy who stands at the intersection where I turn to head home, just off of the free way. I feel so bad for this guy, but I have no idea how to help him. He stands in the middle of the intersection where the light are, balancing on the rocks that are in the cement and he fidgets while holding a sign that says "homeless please help". He looks so ashamed, I can't help but feel so sad every time I see him. I am really bad about carrying cash, so I never have any to give to him, but what would I do, just roll down my window and hand him a $20 bill? Would that really help? Should I make him a bunch of sandwiches? I just don't know.
I would like to think that he's a reasonable guy who's just really down on his luck. He's always clean and wearing clean clothes, his hair isn't a giant matted mess. He looks presentable. Perhaps that's why I'm bothered so much. He doesn't look strung out on something, or like he's been out for a while, he looks new to the homeless game, and it looks like it's wearing on him.
There are times I wish I could just invite him in for dinner and a good night's sleep, but I can't. I have to think of Trixie and her safety.
In the recent months we have donated to a food bank and a homeless shelter for families, so I feel that we've got the donating covered, but seeing one person so sad, I just am at a loss.