SIgnal and Tunnel have superficial similarities. Both are investigative stories with thrill, mystery, suspense, and a time-travel theme in the plot. The 80s is a main time period involved. The acting and music of both shows excellently support both shows.

However, it is because of their differences that I recommend Signal and Tunnel to one another. Each show has their own unique use of time-travel. Their particular time-travel comes with its own limitations and difficulties for the protagonists. Our protagonists’ emotional connections and their interactions with their world are also different because of their particular time-travel.

Signal is a leg above Tunnel because of its tighter plot. Signal’s suspenseful pacing is more gradual, building the tension straight through to the end. Tunnel, meanwhile, has a more episodic cliffhanger thriller pacing. Oh, and Signal has to deal with corruption in its conflict. At least the cops in Tunnel are good cops.

These things made me enjoy Signal and Tunnel as a pair. They have some fundamental differences, bust enough similarities to point out that Signal and Tunnel are two well-made investigation and detective shows that use time-travel well and make it their own.