03 Smells burnt after being on highway

So, I have a 2003 Signature with about 98k miles on it, I just got an oil change at 97k. When I drive around town, everything is fine; I love the car. When I take it on the highway everything is fine. However, after being on the highway for a long period of time (shortest it happened was when I went to Chicago so about 1.5 hours on the highway) and then slowing down to normal speeds I smell sort of a burnt rubber smell. I'm assuming I can't smell it while at high speeds because there is a lot of air to sort of whisk it away. I popped the hood and oil levels were fine and I didn't see anything visible to belt or feel any mushy hoses. I'm no mechanic though, thats for sure. Any ideas as to what might be happening?

I've seen brake pads lock up somewhat and cause a smell similar to burning rubber. I'd jack up the car and try spinning the front wheels. They should easily free wheel.

Also you said you checked the belt which is a good idea. Are all pulleys working properly? Also, with the engine running, watch the belt tensioner for motion when you hit the gas. It should not move. If it moves, it may not be applying enough tension and it may be time for a new one.