Highly optimal TSC systems are not lightyears away. This is compliant and auditable RL-based signal control.

An illustrative four-way signalised junction, seen from above, running a fourteen second cycle. The major road holds green for the first 43% of the cycle and then releases on amber; the minor road then runs green, with a pedestrian crossing phase, before the major road returns. Vehicles queue behind their stop bars and cross only on their own green. Beside the junction, a panel shows the RL model and a decision record cycling through four things: the state observed (density 0.42 vehicles per metre, flow 612 vehicles per hour, south queue six vehicles), the action the model selected (a six second extension of the north–south green, chosen from a bounded action set), the fixed-time plan it replaced (a thirty second fixed phase that would have held regardless of the queue), and the explanation written to the log. The figures and the junction are illustrative and simulated, not measured at a live intersection.