  Ramp metering is the act of controlling on-going vehicles to the highway
mainlines. Decades of practices of ramp metering have proved that ramp metering
can decrease total travel time, mitigate shockwaves, decrease rear-end
collisions by smoothing the traffic interweaving process, etc. Besides
traditional control algorithm like ALINEA, Deep Reinforcement Learning (DRL)
algorithms have been introduced to build a finer control. However, two
remaining challenges still hinder DRL from being implemented in the real world:
(1) some assumptions of algorithms are hard to be matched in the real world;
(2) the rich input states may make the model vulnerable to attacks and data
noises. To investigate these issues, we propose a Deep Q-Learning algorithm
using only loop detectors information as inputs in this study. Then, a set of
False Data Injection attacks and random noise attack are designed to
investigate the robustness of the model. The major benefit of the model is that
it can be applied to almost any ramp metering sites regardless of the road
geometries and layouts. Besides outcompeting the ALINEA method, the Deep
Q-Learning method also shows a good robustness through training among very
different demands and geometries. For example, during the testing case in I-24
near Murfreesboro, TN, the model shows its robustness as it still outperforms
ALINEA algorithm under Fast Gradient Sign Method attacks. Unlike many previous
studies, the model is trained and tested in completely different environments
to show the capabilities of the model.
