No need for lasers at the start line. The starting line clock is simply a display of the finish line laser's clock. They are electronically set simultaneously in one physical location, then one transported to the start line as simply a display. If I wait 30 seconds after my specified minute, so what. I'll just need to average a slightly higher speed. My actual goal is to cross the finish line on time, not to hold a perfect moving average. There is no trigger at the start line. You get a designated starting time and are scored by your difference between your designated start time and actual finish time as recorded by breaking the beam.

As to your secnd question, they do not allow external timers or triggers as you have mentioned. all timing wust be manually controlled. These guys are winning with stopwatches and timers manually activated on the fly. I can manually resynchronize my setup , but I'll have to do it by sight and manual trigger. I can, as stated in a previous part of this post, measure out a fixed distance to a landmark on the last straight 3 mile stretch and hit a button that will automatically adjust my counter to what it SHOULD be at that point, whatever that calculates out to be.