# Enabling Real-Time Phase Control in Traffic Signal Hardware-in-the-Loop Simulation

arXiv: https://arxiv.org/abs/2605.20136 · HTML: https://mlsanity.com/paper/2605.20136/

## Key facts

- Cited by 1 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 19 May 2026.

## Built on by (most cited first, 1 of 1)

- [Sim2Signal: Sim-to-Real Benchmarks for Traffic Signal Control](https://mlsanity.com/paper/2609.01676/) (2026)

## Abstract (arXiv)

Advanced Traffic Signal Control (TSC) algorithms require real-time phase control, yet existing Hardware-in-the-Loop Simulation (HILS) testbeds only support pre-programmed timing plans. In this paper, we present the first HILS testbed for real-time phase control. We develop a novel middleware architecture that translates dynamic phase actions (selection, switch, and duration) into commands for NTCIP-compliant commercial hardware controllers. This middleware manages phase transitions, synchronizes signal states, and handles errors without interrupting the hardware's internal operations. Experimental validation demonstrates that the system executes real-time phase commands, handles system conflicts, and achieves a low system internal latency at sub-millisecond on average.