The route indicators show to the train driver which route the train will take at the junction. In Tunes, the platform 2 exit signal has a route indicator. It's possible to know if the route is set to the Linha do Sul (to Lisbon) or if the junction is set to the most western side of the Linha do Algarve (to Lagos). If the trains takes the left-hand diverging route a 30 km/h (19 mph) speed limit is placed. This speed limit is also set in the platform no.1, which can only be used by train from/to Lagos.
At Tunes train station, track 1 can only be used by trains from/to Lagos. Tracks 3 and 4 only from train from/to Linha do Sul. Only the track 2 (with this route indicator) can be used by trains from/to Lagos AND by trains from/to Linha do Sul.