I think the only time I totally missed a gig was when my alternator went on me while crossing the Gothels Bridge into Staten Island. It was during rush hour and I decided my best chance was to turn around and go back to the NJ Turnpike where I knew there was a service area, hoping that my battery would get me through. Fortunately, I made it back across the bridge, but only to have the car die just after getting to the exit ramp shoulder for the service area. I walked to the service area and called the band leader's wife (this was before cell phones) and AAA. Luckily, it was a paid rehearsal not a full-blown performance.
I've been late a couple of times mostly due to circumstances beyond my control, although one time, pre-Google maps and GPS, I took my host's word for how long it would take me to drive from his house to the hotel where I thought we were playing. It turned out that it took about 30 minutes longer than he had estimated to drive to the wrong side of town and the wrong hotel. I, basically, had passed the correct hotel, which was only about 10 minutes from his house.