Speed Limit Signs

Speed limit signs are pole-mounted structures found on the right side of tracks , designed to inform of the maximum speed that rail vehicles are allowed to travel at. The limit applies to the section ahead of the sign, all the way up to the next speed limit sign or a switch , whichever comes first.

Speed limit signs are circular white boards with a red outline, and a number in the center.

The speed that the sign is limiting to is usually dictated by the physical properties of the track ahead, namely the turn radius of its curves. Going any faster than the limit poses a risk of derailment .

Since trains are long, you need to be aware of not only the speed limit ahead of the train, but also all the way to the rearmost vehicle. For example, when the front end of a train passes a sign with a higher speed limit than the previous, you still need to wait for the rear end to pass it, before accelerating. Otherwise the rear end would go over the limit in its track section, and potentially derail.

The speed limit applies immediately following a sign. Thus, the signs must be observed and reacted to from a distance. That said, signs that show lower limits than the previous are always placed with enough headroom for a train to slow down even after passing them. This is a safety measure, but should not be relied upon outside of an emergency.

To help see them better at a distance, speed limit signs show the speed with fewer digits. Their value is divided by ten, so for example, the limit of 50 km/h is simply shown as "5".

To help anticipate if the next limit will involve a significant change of speed, speed signs are accompanied by appendix signs. If the next limit has a speed increase of 20 km/h or more, a green appendix with an arrow pointing up is added to the sign. Similarly, if the speed limit ahead has a speed decrease of 20 km/h or more, a red appendix with an arrow pointing down is added to the sign.

In Derail Valley the speed limit for going through yards is 30 km/h, except for mainline tracks going through, where the speed limit is 50 km/h. For operations involving contact between vehicles, such as coupling and shunting , the speed limit is 5 km/h.

Installing a distance tracker gadget helps know when the last car has passed the speed limit sign, which can safely increase average speeds .