As a solo traveller, and one who is always on a tight budget and only uses hotels/motels occasionally now, I rarely average more than $50 (inclusive) on a hotel/motel room. When out on the road, look for the hotel/motel discount coupon booklets. There are usually good deals to be had. Just make sure you inspect the room before committing. If you ask, they have to let you. Besides everything else, make sure the smoke detector has not been disabled and that the door has a lock which can not be opened from the outside, such as the chain.

For the rest you could cater much of the food yourself. As mentioned above there are many ways to eat without going to a restaurant. Rest areas, State Parks and Forests and even town parks mostly have picnic tables and sometimes even a grill. But if you carry a small single burner stove, you can make up for where there is none.

As Utahtea mentioned, there are great meals to be had in most supermarkets with the wide variety of salads available today. You will find that with a little thought you can probably cut that food allowance in half. I mostly allow about $20 - $25 dollars per day.

Allow a little to eat out now and then.

Whatever you do, avoid convenience stores and buying drinks or snacks at fuel outlets. Those are the places which eat into your budget.

I would heartily endorse hostels. They are a great place for a solo traveller to stay and meet others. Always make sure they have a locker for each bed, and that you lock it with your own padlock. Carry a medium sized padlock for the purpose. check here for hostels all over North America and read the comments which are posted by independents.

You might like to read through this forum, where many have posted their money saving ideas.

Lifey