traffic lights

what are the laws in the state of texas concerning traffic lights, specificly drive thru yellow light and how are yellow lights timed according to road speed limits

"When a yellow light appears, drivers who are at a distance (from the stop line) greater than their stopping distance will be able to stop comfortably. Drivers who are nearer to the stop line than their safe stopping distance will be able to drive through and clear the intersection. Those who are at or near a safe stop distance away (the "dilemma zone") should be able to (1) either stop, or (2) accelerate (when near the stop line) and clear." (Transp. Engg., Khisty p.271).

The intergreen time (I) is made up of the yellow time plus the all-red time. It is calculated from the formula:
I = Tr + v/2fg + (w+l)/v
where
Tr is the perception-reaction time (1 to 2.5 sec)
v is the speed of vehicle (ft/s)
f is 0.33 (wet) and 0.62 (dry) pvmt
g is 32.2 ft/sq sec
w is distance from stop line until vehicle (rear) is clear
l is length of vehicle