Timing traffic lights is for the begining players. Advanced players start timing school bus stops, garbage trucks, heavy trucks climbing hills and, on two lane roads, left turning vehicles.
Lately, I have been doing an activity that I call route profiling. I have approximated route timings for all of the above (excapt the left turn ones), and also scheduled approximate power settings and/or speeds for all grades, curves and crossings. The route profile also includes a table for expected traffic densities based on the day of the week and transit time. Of course, traffic light cycles are also included where applicable, as well as the traffic monitor rules for traffic aware signals.
No imperical data to report on the effectiveness of this activity yet because the 3-4 MPG FE improvement also contains a component directly attributable to warmer temperatures. It will need more time to see the impact of the developed route profile. But I can say that it does have a positive impact.