Only once at the begining. I was leaning against my truck and clipped in my left foot and pushed myself up straight. As I was looking down (and still not moving) to clip in my right foot I just kept going toward my left side. By the time I figured it out I was laying on the road beside my truck still clipped in with my left foot. The good part was my wife had taken off first and missed it. I came close another time when a car stopped for me and I thoght she was going to pass. I came to a quck stop and almost fell over before I got unclipped. Now it so easy to clip / unclip if it is not a problem at all.