I've fallen over at stoplights exactly twice. Once in my driveway. All three times were my fault. I simply forgot to unclip and lost my balance. The looks from the gal in the car I nearly fell on were priceless. I must have looked like a monkey faced martian clown to her judging by her look in my direction. The one time I got right hooked bad enough to hit the car in front of me, I was riding clipless and it was not a factor.