Yes, as Jake said, you can wear them on the outside but although quiet I am sure they would attract and hold burrs easily. The material is actually very light but strong. I wear mine under my outer garments. The pants have a fly in them which is convenient for obvious reasons and a draw string tie.
I wouldn't want to wear mine as an outside garment. I've had mine for about 3 years now and its been washed several times and shows no sign of wear. I wear mine quite often from early October to mid-January.